An intrinsic physical content of “single photon power” − (hν∙Δν)

Considered in this paper is the possibility to use information properties of photon noise inherent to thermal radiation. Using the calculations of threshold limitations for detecting the fluctuations of thermal radiation as a signal and not disturbances only, we have adduced some arguments concernin...

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Published in:Semiconductor Physics Quantum Electronics & Optoelectronics
Date:2011
Main Authors: Salkov, E.A., Svechnikov, G.S.
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Language:English
Published: Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України 2011
Online Access:https://nasplib.isofts.kiev.ua/handle/123456789/117604
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Cite this:An intrinsic physical content of “single photon power” − (hν∙Δν) / E.A. Salkov, G.S. Svechnikov // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2011. — Т. 14, № 1. — С. 12-20. — Бібліогр.: 27 назв. — англ.

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author Salkov, E.A.
Svechnikov, G.S.
author_facet Salkov, E.A.
Svechnikov, G.S.
citation_txt An intrinsic physical content of “single photon power” − (hν∙Δν) / E.A. Salkov, G.S. Svechnikov // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2011. — Т. 14, № 1. — С. 12-20. — Бібліогр.: 27 назв. — англ.
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container_title Semiconductor Physics Quantum Electronics & Optoelectronics
description Considered in this paper is the possibility to use information properties of photon noise inherent to thermal radiation. Using the calculations of threshold limitations for detecting the fluctuations of thermal radiation as a signal and not disturbances only, we have adduced some arguments concerning the phenomenological content of the “power of a single photon” qΔν ≡ hν∙Δν not defined earlier, where the frequency band Δν is determined by an observation spectral slit. It has been shown that a non-traditional view of “photonic noise” determined by this factor appears in relation with the fluctuations of the photon flux at the observation spectral slit. With definite measurement parameters, this kind of noise is capable to append some essential points to classical models of photon noises and even block access to measurements of fluctuations in the power of thermal radiation. Also adduced are supplementary considerations concerning the existing models of arising shot noise at the photo detector output as a result of physical-and-statistical specificity of the electron excitation process and its kinetics. Offered is a model for a background radiator, which allows us performing the numerical calculations with the use of the specific parameters of the background structure.
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fulltext Semiconductor Physics, Quantum Electronics & Optoelectronics, 2011. V. 14, N 1. P. 12-20. PACS 44.40.+a, 74.40.-n An intrinsic physical content of “single photon power” − (hν⋅Δν) E.A. Salkov, G.S. Svechnikov V. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine 41, prospect Nauky, 03028 Kyiv, Ukraine Abstract. Considered in this paper is the possibility to use information properties of photon noise inherent to thermal radiation. Using the calculations of threshold limitations for detecting the fluctuations of thermal radiation as a signal and not disturbances only, we have adduced some arguments concerning the phenomenological content of the “power of a single photon” qΔν ≡ hν⋅Δν not defined earlier, where the frequency band Δν is determined by an observation spectral slit. It has been shown that a non-traditional view of “photonic noise” determined by this factor appears in relation with the fluctuations of the photon flux at the observation spectral slit. With definite measurement parameters, this kind of noise is capable to append some essential points to classical models of photon noises and even block access to measurements of fluctuations in the power of thermal radiation. Also adduced are supplementary considerations concerning the existing models of arising shot noise at the photodetector output as a result of physical-and-statistical specificity of the electron excitation process and its kinetics. Offered is a model for a background radiator, which allows us performing the numerical calculations with the use of the specific parameters of the background structure. Keywords: thermal radiation, photon noise, fluctuations, power of a single photon. Manuscript received 02.03.10; accepted for publication 02.12.10; published online 28.02.11. 1. Introduction This work is aimed at using the fluctuations of thermal radiation (TR) as a carrier of definite physical information on the radiator. Considering the example of a small size (SR) single radiator within the model of blackbody (BB), we made an attempt to calculate threshold limitations for detecting the intrinsic photon noise of TR as a signal. This approach is justified, first, by perspectives in realization of additional physical information that is contained in the variance of TR noise inherent to SR and has been illustrated in [1-4] as based on the well-known relation between the dispersion 〈ΔF2〉 of a random value F and its mean value 〈F〉: .2 FFqF Δ= (1.1) As always, Exp. (1.1) is used in the form of the so-called relative fluctuation FFqF 2Δ=∗ , which, to some extent, screens the quantitative sign of its physical content qF . The simplest example concerns fluctuations of the charge Q in a capacitor: 192 106.1 −⋅==→⋅=Δ eqQeQ Q where QQQ e Q Qe qQ 1019 104106.1 −− ∗ ⋅ = ⋅ →== . Comprehension of Eq. (1.1) can be founded using the respective analysis of recognized scientific sources [5-16], etc. So, adduced in the papers [1, 2] are the examples of validity for Eq. (1.1) both for the ideal gas thermodynamic and electric current fluctuations in the cases of resistor thermal noise, current shot noise, and the generation – recombination one. It was shown that in the case of adequate statistics the value qF (i.e., the “intrinsic micro-quantity of chaos” [1] that will be renamed as “eigen-parameter”≡“e-p” in what follows) is a physical concept which is fully defined by its content and dimensionality and includes concrete characteristics of a fluctuating physical system. Based on the analysis of the references [5-8, 13-21] and results of researches [1-4] the following improved list of “e-p”≡ qF for the BB TR is proposed: ( )1+= nqn is the “eigen-number” of photons in (BB cavity) TR field, (1.2) © 2011, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine 12 Semiconductor Physics, Quantum Electronics & Optoelectronics, 2011. V. 14, N 1. P. 12-20. ( ) qf nq ν1 Δ⋅+= is the “eigen-flow” BB TR photon within a band of Δνq, (1.3) ( )1ν += nhqE is the “eigen-energy” of TR inside (BB cavity), (1.4) ( ) qV hnq ν1+=ε is the “eigen-density energy” of TR inside (BB cavity), (1.5) ( ) qhnq ν1P Δ⋅ν⋅+= is the “eigen-power” of BB TR within a band of Δνq, (1.6) ( ) q q p V hnq ν1 Δ⋅ ν ⋅+= is the “eigen-power density” of BB TR within a band of Δνq, (1.7) νΔ⋅ν=νΔ hq is “eigen-power-Δν” of BB TR power flow which is restricted in spectral slit with a frequency band Δν. (1.8) Physical parameter Vq in (1.5) and (1.7) is a specific volume which in the case of SR coincides with its real volume. As to the frequency band Δνq in (1.3), (1.6) and (1.7), this has to be defined in accordance with a specific physical situation (problem). The above expressions for qF (1.3)-(1.7) are in accordance with the quantum-mechanical “TR fluctuation factor” ( )1+= n [8, 14-19]. To establish accordance of Eqs. (1.5)-(1.7) to the fluctuations of TR energy density in the BB cavity, one can use the classic formula for the variance ( )λε ( )[ ]2λEΔ [5-7] of the total TR energy ( ) ( )λλ ѓГ⋅= qVE in the BB cavity of a small constant volume1 qV . In accord with the definition [22], the variance of the product of the constant qV and fluctuating ( )λѓГ values is ( )[ ] ( )[ ]222 λεΔ⋅=λΔ qVE . Using qε (1.5) to determine ( )[ ]2λεΔ in accordance with (1.1), one can obtain the following expression: ( )[ ] ( ) =×⋅=Δ ελελ qVE q 22 ( ) ( ) =+⋅ ⋅λ ×λε⋅ n V hcV q q 1 2 (1.9) = ( ) ( )nhcE +⋅ λ ×λ 1 , which is the Einstein formula [5-7]. Being based on (2.8) and using Eqs (1.5), (1.7), considered in the works [3, 4] was the calculation model of the principle for distant © 2011, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine 1Volume that did not lose its space-time relation with the number of modes of an actual frequency in its cavity yet [13]. identification of both single SR and the stochastic set (“cloud”) of SR [4]. It is noteworthy that while determining the thresholds for detecting the intrinsic fluctuations of TR SR BB power the “problem of the single photon power” is solved. Thus, in the literature devoted to TR and its fluctuations (e.g. [8] and so on) one can find the understandable by its dimensionality self-sufficient expression [ ]-1sergѓЛѓЛ ⋅Δ⋅h , but it, as an acting physical value, does not find its specific phenomenological interpretation. As it will be shown below, this enigmatic single-photon power νν Δ⋅h can play a rather essential role and obtain definite phenomenological interpretation. Expediency of using the property (1.1) in the case of TR SR seems to be obvious as, in spite of wide applications of laser technologies, TR is inherent to any objects both natural and technological cloud-like SR systems. 2. Fluctuations of TR in terms of the “eigen-parameter” 2.1. Initial conceptions. It is obvious that only using measurements of the TR power emitted by SR and fluctuations of this power one can obtain some information included in TR of SR. As to TR, the property (1.1) can be applied beyond controversy, and first of all, due to the fact that photons do not interact with each other (see e.g. [7, 15-17]). In what follows, we shall consider the problem of physical informativity inherent to the TR noise variance in the most accessible form. Here, we originate from the opportunity to use the following approach: TR power variance is written in accordance with relations (1.1) and (1.5)-(1.7) when determining the thresholds for registration of the TR power variance for SR within the model of BB with the dimension corrections [23, 24]. Further, we shall use the following designations: qF ≡ “e-p” ; c – light speed, ν − frequency (and the respective wavelength − λ = c/ν) of observed TR, which corresponds to the middle of Δν (or Δλ) which is a spectral band for observations; 1 1exp − ⎥ ⎦ ⎤ ⎢ ⎣ ⎡ −⎟ ⎠ ⎞ ⎜ ⎝ ⎛ ⋅ = kT hcn λ is the Planck function, ( ) 3 2 ν8νν c VZ Δν⋅π ⋅=Δ⋅ is the number of TR spatial modes within the spectral frequency band Δν inside the BB cavity with the volume V = R3; ( ) i i i n R hc ⋅⎟ ⎠ ⎞ ⎜ ⎝ ⎛ Δ⋅ ⎥ ⎥ ⎦ ⎤ ⎢ ⎢ ⎣ ⎡ −⋅⋅= λ λλ λλ λε 2 2 3 4 1ѓО8 is the TR energy density inside the SR cavity of a cubic shape with the dimensional correction ⎥ ⎥ ⎦ ⎤ ⎢ ⎢ ⎣ ⎡ − 2 2 4 1 iR λ [23, 24] that limits the number of TR modes in the volume ; the 3 ii RV = 13 Semiconductor Physics, Quantum Electronics & Optoelectronics, 2011. V. 14, N 1. P. 12-20. © 2011, V. Lashkaryov Institute of Semiconductor o ces of e 14 ) Physics, National Academy f Scien Ukrain ratio in the expression for is kept constant during spectral calculations or measurements (hereinafter, the subscript “i” means belonging to SR) . ( λλΔ / ( )λε i 2.2. The model of background TR radiator To calculate fluctuations of an arbitrary large background radiator, it is necessary to know the size “eigen-volume” for this background (Vq – in formulas (1.5) and (1.7)), which is not described in literature accessible to the authors (for instance, [6-8, 14-21] and so on). To solve the problem, one needs the model of a background radiator, which is capable to provide more or less adequate results for numeral calculations of the fluctuation variance for TR background 2 jBPΔ (hereinafter, the subscripts “j” and “B” mean belonging to background elements). Let us assume the following simplified model: in a warm background (B) an ideal photodetector (PD) registers TR from a single SR of a cubic shape with the constant cavity volume Vi = Ri 3 cm3; let the size of radiating area be equal Si ≈ Ri 2. The model of such a background2 (Fig. 1) that provides the possibility for a well grounded calculations of the TR background power seems as follows. Within the boundaries of the observed background area , the area , serves as the emitting one (see the subscript “B”) that consist of identical and small in their obsS jBjBB NPS ⋅Δ= 2 jBN sizes stationary radiators (with their non-fluctuating volume ). When using the dimensional corrections 3 jBR jBN 2 Any other model suitable for numeral calculations of the background TR dispersion (except the offered one) is not known for the authors; therefore they did not make respective references. [23, 24] to small radiators, we consider their size in calculations as close to ( ) ( )22 2 ijB RR ≈ . In calculations below, we shall use the following numeric parameters for the model of the background (Fig. 1): ( ) ( ) 22 22 cm000064.0002.0004.0002.0 cmSpacingSpacing =−++= =++= jBjB RS jBN obsS . Density inside is ( ) 2- 2 cm15625 cm008.0 11 ===Γ jB jB S obsjBjB SN, Γ ⋅= iD BDL BS Dr 22 Dr⋅π . To simplify the formulas, we use the “lensless3 ” choice of the system “radiators (SR + B) - photodetector (PD)”. The values l and correspond to distances from SR and its background to PD, respectively. The input PD hole can be defined via the radius ; the value will serve as an area of the PD photosensitive element. Joint action of the TR system (SR + B) on PD will depend on spatial apertures in accordance with the above approximations that do not contradict to the conventional ones [25]: the aperture, within the boundaries of which PD registers TR of a single SR is ⎟⎟ ⎠ ⎞ ⎜⎜ ⎝ ⎛ ⋅≅ 2 2 2 iD D iiD l rSA jBN , and the background aperture given the number of elements is ⎟ ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎜ ⎝ ⎛ ⋅ ⋅⋅= 22 2 BDL Dr jBNjBSBDA . In the offered model, the spectrum of TR power that is emitted by SR into semi- Fig. 1. The model of a background (a), and a geometry of the system (b). 3 As the considered version of the problem has an illustrative character of calculations, small numeral errors will not impact on results and conclusions of principle. Semiconductor Physics, Quantum Electronics & Optoelectronics, 2011. V. 14, N 1. P. 12-20. © 2011, V. Lash miconductor Physics, National Academy of Sciences of Ukraine 15 ( ) karyov Institute of Se space can be defined as ( ) 2 2 4 iii RcP ⋅⋅λε=π (see [8], p. 5, (1.9)), and its fraction that excites PD can be written as: ( ) ( ) 2 2 2 24 iD D iiiD l r RcP ⋅⋅⋅λε=λ . (2.1) The variances of the TR power both from SR and background single element are defined in accordance with [22] as variances of the product of fluctuating ( and jBN ( )λεi ( )λε Φj ) and constant ( and ) values. The spectrum of the signal, i.e., the variance of the SR TR power (2.1) with account of (1.1) and (1.7) becomes (when ): iDA BDA 3 iq RV = =⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ ⋅⋅⋅=Δ 2 2 2 222 24 ѓГ iD D iiiD l r RcP ( ) . 24 1 24 ѓГ 2 2 2 32 2 2 ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ ⋅⋅⋅+⋅ ⋅ ⋅⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ ⋅⋅⋅ iD D ii iiD D ii l r Rcn R hc l r Rc λ (2.2) By its analogy with (2.1) and (2.2), let us define the power ( ) π2jBP and the variance of TR emitted by small background elements . In the case of statistical independency inherent to TR processes from background elements, a constant value of their number , sizes and location within the boundaries of , the total power of the background TR at the PD input can be written as jBN jBN jBR obsS ⎟⎟ ⎠ ⎞ ⎜⎜ ⎝ ⎛ ⋅⎟ ⎠ ⎞ ⎜ ⎝ ⎛ ⋅⋅⋅= π 2 2 2 2 24 ε BD D jBjBjBBD L r RcNP . (2.3) The dispersion of the sum (2.3) defined as the sum of the dispersions for separate background elements 2 jBPΔ using the Burgess4 theorem for = const in accord with (1.1) and (1.7) acquires the following form jBN ( ) . 24 1 24 ѓГ 2 2 2 3 2 2 22 ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ ⋅⎟ ⎠ ⎞ ⎜ ⎝ ⎛ ⋅⋅+⋅ ⋅ × ×⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ ⋅⎟ ⎠ ⎞ ⎜ ⎝ ⎛ ⋅⋅⋅=Δ iD D jBjB jB iD D jBjBjBBD L r Rcn R hc L r RNcP λ (2.4) 3. Photocurrents at the output of an ideal PD Descending to the photoelectric currents corresponding to the SR TR powers (2.1), (2.2) and SB TR (2.3), (2.4), let us remind you about the important property of the principle adduced in [26]: 4Burgess R.E. Faraday, Soc.Discussions, 1959, v.28, p.151; reference cited in [20]. “… the spectrum of photocurrent power reconstitutes the optical spectrum independently of the optical field statistics”. It is this condition that allows us prolonging our consideration of the problem formulated in the Introduction. In the model adopted above for the background and the scheme of joint exciting the photodetector by the system (SR + B), acting at the PD output are the currents (3.1)-(3.6) defined in accordance to the conventional rules [8]. Originating from relations (2.1)-(2.4), at the output of ideal PD we have (e is the electron charge, η - quantum efficiency of PD): − the stationary current caused by SR TR power (2.1) iDiD P h eI ⋅⎟ ⎠ ⎞ ⎜ ⎝ ⎛ ⋅ = ν η ; (3.1) − the respective iDI (3.1) shot noise iDisn IfeI ⋅Δ⋅⋅=Δ 22 ; (3.2) − the signal corresponding to the SR TR variance (2.2) ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ νΔ Δ ⋅⋅Δ⋅⎟ ⎠ ⎞ ⎜ ⎝ ⎛ ν ⋅η =Δ fP h eI iDiD 22 2 2 ; (3.3) − the current corresponding to the background TR power (2.3) BDBD P h eI ⋅⎟ ⎠ ⎞ ⎜ ⎝ ⎛ ⋅ = ѓЛ ѓЕ ; (3.4) − the corresponding BDI (3.4) shot noise BDBsn IfeI ⋅Δ⋅⋅=Δ 22 ; (3.5) − the current corresponding to the background TR dispersion (2.4) ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ νΔ Δ ⋅⋅Δ⋅⎟ ⎠ ⎞ ⎜ ⎝ ⎛ ν ⋅η =Δ fP h eI BDBD 22 2 2 . (3.6) The coefficient ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ νΔ Δ ⋅ f2 [8] in (3.3) and (3.6) defines, to some extent, the fraction of chaotic fluctuations inherent to TR within the band Δν at the PD input, which is really registered as a chaotic in time current at the PD output within the frames of its electron band of frequencies Δf. When calculating and measuring the current and power spectra corresponding to TR, the values ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ νΔ Δ ⋅ f2 in formulas (3.3), (3.6) can be kept constants, by changing the electron band of frequencies (e.g., at 210−=⎟ ⎠ ⎞ ⎜ ⎝ ⎛ νΔ Δf and 210−=⎟ ⎠ ⎞ ⎜ ⎝ ⎛ λ λΔ one has 4 6 10 103 −⋅λ ⋅ =Δf ). Semiconductor Physics, Quantum Electronics & Optoelectronics, 2011. V. 14, N 1. P. 12-20. 4. Thresholds for detection of single SR TR fluctuations by an ideal PD 4.1. Detection thresholds 2 iDPΔ on the background of intrinsic noises (single-noise-limited detection – SNLD mode [8]) Before starting our consideration of the main task (as to the threshold values (3.3)) formulated above, let us remind you about the problems that contain some conceptions poorly ascertained from the physical viewpoint. Let us define the threshold values thiDP (2.9) and thiDP2Δ (2.2) via the signal-to-noise ratio for respective “measured” currents revealed with the background of intrinsic noises. Extrinsic noises are absent here. 1) As always, the threshold thiDP is defined by the following TR power η Δ⋅ν⋅ = fhP thiD 2 [8] by detection of the signal thiDI (3.1) with the background 2 isnIΔ (3.2). In this case, there are no explanations why the noises 2 iDPΔ related to the intrinsic fluctuations of TR in a BB cavity5 of the radiator are not taken into account. At the same time, the very combination can be hardly explained in a phenomenological aspect. But taking fh Δ⋅ν⋅2 2 iDIΔ into account together with 2 isnIΔ results in a more informative expression (the essence of SNLD condition [8] remains valid), namely: ( ) ⎟ ⎟ ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎜ ⎜ ⎝ ⎛ ⎟⎟ ⎠ ⎞ ⎜⎜ ⎝ ⎛ ⋅ ⋅+⋅ ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ λ λΔ ⋅⋅ λ ⋅+⋅ Δ⋅ ⋅= 2 2 2 1 4 η1 η ν2 iD D i i thiD l rn R fhP , (4.1) which contains definite information upon this radiator and its aperture (Fig. 2). 2) After respective simple algebraic operations with account of expressions (2.1), (2.2) and (3.1)-(3.3), the threshold values for the signal of our interest 2 iDIΔ (3.3) against the background of the intrinsic shot noise 2 isnIΔ (3.2) can be reduced to the following expression ( ) ⎭ ⎬ ⎫ ⎩ ⎨ ⎧ νΔ⋅ =⎟⎟ ⎠ ⎞ ⎜⎜ ⎝ ⎛ ⋅⋅⋅+⋅ ⋅λ η ν 4 1 2 2 2 3 h l rRcn R hc i D ii i . (4.2) © 2011, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine 5 Definition and measurement of the noise-coefficient for semiconductor photodiodes takes into account the photon-noise stated in the paper [27] but doesn’t consider the specific parameters of the radiator (except for (〈n〉+1) [8, 14-19]) as well as the aperture features. Fig. 2. Spectral dependences of η ν fhP thiD Δ⋅⋅ = 2 (curve n(λ)) and thiDP (4.1) at two distances to the radiator (size Ri = 20 μm): liD = 10 cm (curve R(λ)), and liD = 5 cm (curve r(λ)). It is obvious that (4.2) describes equality of two “intrinsic powers”: on the left – “e-p” (1.7), (“intrinsic micro-quantity of chaos” in terms [1, 2]) that corresponds to the frequency band defined via the aperture factor and the SR intrinsic volume (1.5), (1.7), i.e. qνΔ qii VRV ≡= 3 ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ ⋅ ⋅ ⋅ =Δ≡Δ 2 2 22 i D i iq l r R cνν ; on the right – “single photon power ” defined through the optical observation band divided by the value of PD quantum efficiency: ⎭ ⎬ ⎫ ⎩ ⎨ ⎧ νΔ⋅ =νΔ η νhq . (4.3) This “single photon power” occurs in [8] (e.g. page 87) also as the factor defining power within a single mode of TR, namely: “…the power per mode is νΔνε= hfP kk …”; here, is emissivity and fε k – Bose- Einstein occupancy probability. It seems very doubtful that to determine the single mode TR power one use the spectral frequency band νΔ . As it follows from the commonly known literature, the TR power within the band νΔ quantifies the number of modes ( ) νΔ⋅zZ (see the above item 1.2) in the range of which it is observed (measured) or calculated. The equality νΔ= qqp (4.2) puts more definite phenomenological content into the value (4.3), since the equality (4.2) also defines the value as “e-p” in the list (1.2)-(1.8), taking into account the physical sense of (1.7). In what follows (see the item 4.2 below), our reasoning in regard to the physical meaning of the “power = νΔq νΔq pq νΔνh ” confirms the validity of consideration of the detection thresholds 2 iDIΔ (3.3) with the total noise background: (3.2), (3.5), and (3.6). 16 Semiconductor Physics, Quantum Electronics & Optoelectronics, 2011. V. 14, N 1. P. 12-20. 4.2. Detection thresholds 2 iDPΔ in presence of external thermal noise When calculating the thresholds of the signal 2 iDIΔ , the total current that takes into account external noises will be defined using the following logic. The fluctuating total virtual current 2 ΣΔI measured by a PD in view of statistical independency for the currents (3.2), (3.5), (3.6) and containing only averaged values will be determined via the sum of variances in the accepted approximation ( ) νΔ Δ ⋅⋅⋅⎟ ⎠ ⎞ ⎜ ⎝ ⎛ λ ⋅η +⋅⎟ ⎠ ⎞ ⎜ ⎝ ⎛ λ ⋅η ⋅Δ+ νΔ Δ ⋅Δ⋅⎟ ⎠ ⎞ ⎜ ⎝ ⎛ λ ⋅η +⋅⎟ ⎠ ⎞ ⎜ ⎝ ⎛ λ ⋅η ⋅Δ=Δ Σ fPq hc eP hc efefP hc eP hc efeI BDjpBDiDiD 2 // 22 // 2 2 2 2 2 . (4.4) Having used (4.4) and (3.1)-(3.6) to write the signal-to-noise ratio via PD output currents expressed through the corresponding TR power at the PD input one has ( ) ⎥ ⎥ ⎦ ⎤ ⎢ ⎢ ⎣ ⎡ Δ Δ ⋅⋅⋅⎟ ⎠ ⎞ ⎜ ⎝ ⎛ ⋅ +⋅⎟ ⎠ ⎞ ⎜ ⎝ ⎛ ⋅ ⋅Δ+⋅⎟ ⎠ ⎞ ⎜ ⎝ ⎛ ⋅ ⋅Δ Δ Δ ⋅Δ⋅⎟ ⎠ ⎞ ⎜ ⎝ ⎛ ⋅ = Δ−Δ Δ Σ νλ η λ η λ η νλ η f Pq hc eP hc efeP hc efe fP hc e II I BDjpBDiD iD iD iD 2 // 2 / 2 2 / 2 2 2 22 2 . (4.4*) Let us cancel (like in Eq. (4.1)) all the reducible terms in the numerator and denominator. After this conventional procedure [8] for conversion from PD currents to TR powers, the threshold condition for thiDP2Δ (4.4*) can be reduced to the following form ( ) 1 2 = ⋅⋅+Δ⋅⋅+Δ⋅⋅ Δ ⋅ BDjpBDiD thiD PqhPhP P ηνννν η . (4.5) The formula (4.5) considered definition (1.1) and physical meaning of the equality (4.2) allows to consider the expression ( ) iDPh ⋅νΔ⋅ν in the denominator (4.5) as the variance of (2.1) related to the “photon noise at the spectral slit”. Let us designate it as iDP ( ) iDPhP ⋅νΔ⋅ν=Δ νΔ 2 . (4.6) The same reasoning concerns the expression ( ) BDPh ⋅νΔ⋅ν , too. The factor is physically defined as “e-p” (1.8) for TR power flowing through an observation spectral slit (“e-p” for slit-fluctuation). This “Δ-noise” (4.6), created artificially to some extent, is defined via the above list of “e-p” (1.2)-(1.8). νΔν=νΔ hq νΔ To put more definite phenomenological meaning into the values and νΔq 2 νΔΔP , let us consider spectral and quantitative (calculated) features of the signal threshold values thiDP2Δ as compared with the spectra of νΔ Δ 2 iDP and the signal 2 iDPΔ . In the above accepted model for the background (§1, item 1.3) given the definitions (3.1) to (3.6) as well as expressions (4.5), (4.6), the spectral dependence of the threshold power 2 iDPΔ for the signal defined through the respective photocurrent at the PD output thiDI 2Δ in terms of wavelengths λ and for η = 1 can be expressed as follows ( ) BD jB D jBjB jB iDthiD P L rRcn R chcPchcP ⋅ ⎥ ⎥ ⎦ ⎤ ⎢ ⎢ ⎣ ⎡ ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ ⋅ ⋅⋅⋅+⋅+⎟ ⎠ ⎞ ⎜ ⎝ ⎛ λ λΔ ⋅ λ ⋅ λ +⋅⎟ ⎠ ⎞ ⎜ ⎝ ⎛ λ λΔ ⋅ λ ⋅ λ =Δ 2 2 2 3 2 24 11 . (4.7) Being targeted to compare the spectra of the noise signal (2.10) and “Δ-noise” (4.6) with those of the signal threshold (4.7) for various temperatures, we have depicted them in Figs 3 and 4. The signal (2.2) defined via the current (3.3) takes the detailed look: © 2011, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine 17 Semiconductor Physics, Quantum Electronics & Optoelectronics, 2011. V. 14, N 1. P. 12-20. ( ) 2 2 2 2 3 2 3 2 24 11 2 18 ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ ⋅ ⋅⋅⋅+⋅⋅⋅ ⎥ ⎥ ⎦ ⎤ ⎢ ⎢ ⎣ ⎡ ⎟⎟ ⎠ ⎞ ⎜⎜ ⎝ ⎛ −⋅⎟ ⎠ ⎞ ⎜ ⎝ ⎛ Δ⋅⋅=Δ iD D ii i i i iD l r Rcn R n R hcP λ λ λ λ π λ . (4.8) “Δ-noise” (4.6), also in the detailed notation, is as follows: ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ ⋅ ⋅⋅⋅⋅⎟ ⎠ ⎞ ⎜ ⎝ ⎛ λ λΔ ⋅⎥ ⎦ ⎤ ⎢ ⎣ ⎡ ⋅ λ −⋅ λ π ⋅⎟⎟ ⎠ ⎞ ⎜⎜ ⎝ ⎛ ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ λ λΔ ⋅ λ ⋅ λ =Δ νΔ 2 2 2 2 2 3 2 244 18 jB D ii i L rRcn R chcP (4.9) © 2011, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine The parameters of the SR and the respective background are chosen first of all considering the necessity to simplify our phenomenological analysis. The numeral values of threshold powers thiDP2Δ for the chosen parameters are determined for the wavelength (shown with arrows ↓ in Fig. 3) of the intersection points between the signal spectrum (4.8) and those of its threshold values (4.7) for various temperatures. Fig. 3. Illustration of spectral distributions of TR powers (4.8), (4.9) and signal thresholds (4.7) )(2 λ=Δ BP thiD for three temperatures (TjB) of background radiators. The designations and numeral parameters: ( ) iBTthiDPB 2Δ=λ ; ( ) SIGNAL K600 2 ≡Δ=λ thiDIS ; ( ) "noise" K600 2 −Δ≡Δ=λΔ Δ thiI ; ( ) ( ) ( )222222 8.22002.02 ⋅=⋅= iDDiiD lrRA ; TSR = 600 K; ; -310/ =λλΔ ( ) ( ) ( )[ ]22242 600.223010563.1004.0 ⋅⋅⋅⋅=iBA ; ; T-310/ =λλΔ jB = 300, 150, 90, 60 K. Further comparison of these spectra shows that measuring the signal thresholds thiDP2Δ is not always possible. If the observation parameters are chosen differently, “Δ-noise” (4.9), (designated as )(λΔ in Fig. 3), when )Q()( λ>λΔ , the signal spectra are “blocked” by photon flux fluctuations at the spectral slit, that is by the “Δ-noise” (4.9). As it follows from Figs 2 and 3, there are specific circumstances (e.g., mutual combinations of numeral characteristics inherent to a radiating system SR+BG as well as parameters of measuring process) when fluctuation limitations (like the usual shot noise) for measurements of TR signal threshold characteristics arise in the course of TR flux passing within an optical band Δν inside a detecting apparatus before reaching the sensitive element of PD. In the literature (see, for instance, [6-8, 14-21]) TR fluctuations of this kind were not considered. However, as it follows from Figs 3 Fig. 4. Illustration of “blocked” spectral distributions of TR powers (4.8), (4.9) and signal thresholds (4.7) )(2 λ=Δ TP thiD for three temperatures (TjB) of background radiators. The designations and numeral parameters are same as for Fig. 3. 18 Semiconductor Physics, Quantum Electronics & Optoelectronics, 2011. V. 14, N 1. P. 12-20. and 4, one should not neglect the intrinsic TR noises (4.5) and (4.8) within the spectral band. Thus, for example in [8] the shot noise related to a photocurrent is calculated in the traditional way when originating only from statistical (or in [17] from quantum-and-statistical) notions as to appearance of electrons in the PD active area when these are excited by photons. In relation with the considered problem, there arises the following question: is it possible that the measured photocurrent shot-noise is always determined by random electrons appearing statistically inside the photosensitive area of PD? 5. Conclusions 1. Conversion of the common threshold expression in current terms at the PD output to that (4.5) for the respective TR powers at the PD input results in the expression for an additional photonic noise that arises due to limitations of spatial-and-time conditions for TR flux passing through the observation slit . As a result, the process of detection is limited by the “photonic νΔ νΔ - noise” ( ) iDPhP ⋅νΔν=Δ νΔ 2 , (4.6), along with the traditional “electron shot noise”. 2. As an “eigen-parameter” (in terms of [1, 2] it is the “intrinsic micro-quantity of chaos”) in this case we deal with well-known but a phenomenologically unascertained up to date “single photon power” . νΔν=νΔ hq 3. Inclusion of the “power” (4.3) in the list (1.2)-(1.8) as an “intrinsic power of TR flux” (1.8) seems to be adequate. From a phenomenological viewpoint, the “power” defines the dispersion of additional photonic fluctuations in the TR flux through an observation slit . νΔq νΔq νΔ 4. In the case of photoelectronic detection the TR signals at the PD output, along with traditional photonic (3.3) and shot noises [8, 10], it seems reasonable to take into account the “photonic νΔ -noises” (4.6) considered above (Figs 3 and 4). 5. Used in this work a rather risky approximation (first of all, ignoring the correlation processes, moments of higher orders, etc. [17]) does not reduce to zero the above considered physical concepts as well as their role and numeric values. Thus, the following result is non-trivial: it is possible to measure a numeral meaning of the physical value “power of a single photon” under specific physical conditions (with the cold enough background: e.g. in Fig. 4 it can be realised at T νΔν=νΔ hq jB < 120 K and high enough ratio ν Δν ∼ 0.1) only by measuring (with an ideal PD) the TR flux fluctuations at the spectral slit ѓЛΔ . References 1. E.A. Salkov, Intrinsic micro-quantity of chaos (thermal black body radiation, photocurrents) // Opto-Electron. Rev. 6, No.4, p. 251-256 (1998). 2. E.A. Salkov, Microscopic parameters of stochastic system and variance of physical quantity (ideal gas, electric currents, thermal black body radiation) // Semiconductor Physics, Quantum Electronics & Optoelectronics 1(1), p. 116-120 (1998). 3. E.A. Salkov, G.S. Svechnіkov, On thermal emission of small-sized radiators // Semiconductor Physics, Quantum Electronics & Optoelectronics 6(2), p. 205-209 (2003). 4. E.A. Salkov, G.S. Svechnikov, G.A. Shepelsky, Remote identification of small-size radiators by the thermal radiation of their stochastic totality // Ukr. J. Phys. 50(9), (2005). 5. L.D. Landau, Ye.M. Lifshits, Statistical Physics (Theoretical Physics, V. 5). Nauka, Moscow, 1964 (in Russian). 6. C.V. Heer, Statistical Mechanics, Kinetic Theory and Stochastic Processes. Academic Press, New York, London, 1972. 7. P. Loudon, The Quantum Theory of Light. Clarendon Press, Oxford, 1973. 8. R.H. Kingston, Detection of Optical and Infrared Radiation, In: Springer Series in Optical Science, Vol. 10. Springer-Verlag, Berlin-Heidelberg-New York, 1978. 9. B.R. Levin, Theoretical Basics of Statistical Radio- engineering. Book 1. Moscow, Sovetskoye radio, 1969 (in Russian). 10. Ya.P. Terletskyi, Statistical Physics, 2-nd ed. Moscow, Vysshaya shkola, 1973 (in Russian). 11. a) V.G. Levich, Introduction to Statistical Physics. Moscow, Gosizdat tekhniko-teoreticheskoi literatury, 1954 (in Russian); b) V.G. Levich, Theoretical Physics, V. 1. Moscow, Nauka, 1969 (in Russian). 12. Yu.B. Rumer, M.Sh. Ryvkin, Thermodynamics, Statistical Physics and Kinetics. Moscow, Nauka, 1977 (in Russian). 13. L. Brillouin, Quantum Statistics. Translated from French by A. Prikhot’ko and D. Gogoberidze. Gosudarstvennoye nauchno-tekhnicheskoye izdatel’stvo Ukrainy, Khar’kov-Kiev, 1934 (in Russian). 14. R.H. Fowler, Statistical Mechanics, 2-nd ed. Cambridge University Press, New York, 1936. 15. F.T. Arekki, Statistics of photons. In: Photonics. Moscow, Mir, 1978 (in Russian). 16. M. Bertolotti, Statistics of photons, In: Spectroscopy of Optical Mixing and Correlation of Photons. Translated from English. Moscow, Mir, 1978, p. 46-70 (in Russian). © 2011, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine 17. Leonard Mandel, Emil Wolf, Optical Coherence and Quantum Optics, Ch. 9 and 12. Cambridge University Press, USA, 1995. 19 Semiconductor Physics, Quantum Electronics & Optoelectronics, 2011. V. 14, N 1. P. 12-20. 18. R. Clark Jones, Noise in radiation detectors // Proc. IRE, paper 3.3.7, p. 1481-1486 (1959). 19. John A. Jamieson, Raymond H. McFee, Gilbert N. Plass, Robert H. Grube, Robert G. Richards, Infrared Physics and Engineering. McGrow-Hill Book Company, Inc., New York-Toronto-London, 1963. 20. Albert van der Ziel, Noise. Sources, Characte- risation, Measurement. Prentice-Hall Inc., Englewood Cliffs, N.Y., 1970. 21. E.L. Dereniak, J.D. Boreman, Infrared Detectors and Systems. John Wiley & Sons, Inc., New York- Chichester-Brisbane-Toronto-Singapore, 1994. 22. B.V. Gnedenko, Theory of Probabilities. Moscow, Nauka, 1969 (in Russian). 23. A.A. Kolokolov, G.V. Skrotskyi, Equilibrium radiation within a cavity of finite sizes // Optika i spektroskopiya, 36 (2), p. 217-221, 1974 (in Russian). 24. H.P. Baltes, F.K. Kneubuhl, Thermal radiation in finite cavities // Helv. Phys. Acta, 45, p. 481-529 (1972). 25. U. Wolf, Radiometry, In: Applied Optics and Optical Engineering, Vol. VIII, Ch. 5. Academic Press, 1980. 26. G.Z. Kammins, Spectroscopy of optical mixing, In: Spectroscopy of Optical Mixing and Correlation of Photons. Translated from English. Moscow, Mir, 1978, p. 221-231 (in Russian). 27. G. Spescha, M.J.O. Strutt, Definition und Messungen der Rauschzahl von Halbleiter- Photodioden, einschliesslich Photonenrauschen // Sci. Electrica, 4, p. 21-132 (1959). © 2011, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine 20
id nasplib_isofts_kiev_ua-123456789-117604
institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
issn 1560-8034
language English
last_indexed 2025-12-07T16:22:49Z
publishDate 2011
publisher Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України
record_format dspace
spelling Salkov, E.A.
Svechnikov, G.S.
2017-05-25T16:16:26Z
2017-05-25T16:16:26Z
2011
An intrinsic physical content of “single photon power” − (hν∙Δν) / E.A. Salkov, G.S. Svechnikov // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2011. — Т. 14, № 1. — С. 12-20. — Бібліогр.: 27 назв. — англ.
1560-8034
PACS 44.40.+a, 74.40.-n
https://nasplib.isofts.kiev.ua/handle/123456789/117604
Considered in this paper is the possibility to use information properties of photon noise inherent to thermal radiation. Using the calculations of threshold limitations for detecting the fluctuations of thermal radiation as a signal and not disturbances only, we have adduced some arguments concerning the phenomenological content of the “power of a single photon” qΔν ≡ hν∙Δν not defined earlier, where the frequency band Δν is determined by an observation spectral slit. It has been shown that a non-traditional view of “photonic noise” determined by this factor appears in relation with the fluctuations of the photon flux at the observation spectral slit. With definite measurement parameters, this kind of noise is capable to append some essential points to classical models of photon noises and even block access to measurements of fluctuations in the power of thermal radiation. Also adduced are supplementary considerations concerning the existing models of arising shot noise at the photo detector output as a result of physical-and-statistical specificity of the electron excitation process and its kinetics. Offered is a model for a background radiator, which allows us performing the numerical calculations with the use of the specific parameters of the background structure.
en
Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України
Semiconductor Physics Quantum Electronics & Optoelectronics
An intrinsic physical content of “single photon power” − (hν∙Δν)
Article
published earlier
spellingShingle An intrinsic physical content of “single photon power” − (hν∙Δν)
Salkov, E.A.
Svechnikov, G.S.
title An intrinsic physical content of “single photon power” − (hν∙Δν)
title_full An intrinsic physical content of “single photon power” − (hν∙Δν)
title_fullStr An intrinsic physical content of “single photon power” − (hν∙Δν)
title_full_unstemmed An intrinsic physical content of “single photon power” − (hν∙Δν)
title_short An intrinsic physical content of “single photon power” − (hν∙Δν)
title_sort intrinsic physical content of “single photon power” − (hν∙δν)
url https://nasplib.isofts.kiev.ua/handle/123456789/117604
work_keys_str_mv AT salkovea anintrinsicphysicalcontentofsinglephotonpowerhνδν
AT svechnikovgs anintrinsicphysicalcontentofsinglephotonpowerhνδν
AT salkovea intrinsicphysicalcontentofsinglephotonpowerhνδν
AT svechnikovgs intrinsicphysicalcontentofsinglephotonpowerhνδν