CN102768069A - Single-photon spectral counting and imaging system and method for complementary measurement - Google Patents

Abstract

The invention provides a single-photon spectral counting and imaging system and method for complementary measurement. According to the system, a plurality of single-photon dot detection units corresponding to different wavelengths are respectively selected in a visible range and a near infrared range so as to form two linear arrays which are distributed in exit directions of two arms of a spatial light modulator together with a spectral light splitter. The method comprises the following steps that: the spatial light modulator reflects the light imaged on the spatial light modulator to the two arms and respectively collimates and splits the light, visible spectrum is taken by one arm, and near infrared spectrum is taken by the other arm, so that the light can be detected by the corresponding linear array of the single-photon detector. According to the wavelength information corresponding to a complementary matrix, count values and a channel, visible and near infrared color images can be rebuilt with a related compressed sensing algorithm and a spectrogram for wavelength-optical power can be counted for spectral analysis. The system and the method disclosed by the invention solve the problem that the existing imaging spectrograph cannot simultaneously detect spectra of the visible light and the near infrared light, and have the advantages of low dimension, high flux, high sensitivity, high resolution and the like.

Description

A kind of single photon spectrum counting imaging system and method for complementary measurement

Technical field

The present invention relates to the technical field of utmost point low light level imaging spectral, particularly a kind of single photon spectrum of complementary measurement counting imaging system and method.

Background technology

In emerging high-tech areas such as light spectrum image-forming Measurement and analysis, biological detection, starry sky detection, night vision observation, utmost point weak light detection, concentration detection, remotely sensed image, imaging of medical, monitoring; Not only need survey the utmost point low light level; Also to carry out the composition distributional analysis to several spectral bands; And the imaging spectral of visible light is surveyed and can't be satisfied the demands, and scientists more often need be known the spectral information of near infrared light wave band.In addition, existing imaging spectral instrument is insensitive to the utmost point low light level, adopts scan mode mostly, and poor stability is difficult to reach the requirement of imaging high precision.Because laser instrument is generally operational on the wavelength of frequency multiplication; Wavelength coverage is limited; Conventional imaging detector also only is operated in visible light wave range; Check and analysis when be difficult to realizing that utmost point low light level object carried out the wide range component distributing of visible light and near infrared light are demanded a kind of brand-new imaging spectrum system urgently and are satisfied growing scientific research demand.

The present invention arises at the historic moment for addressing the above problem, and also is based on the improvement and the innovation of previous work simultaneously.In this area; This research institute has a related patent U.S. Patent No.: " a kind of utmost point low light level multispectral imaging method and system thereof " (application number or patent No.: 201110166471.6; Applicant or patentee: Space Sci. & Application Research Center, Chinese Academy of Sciences), thus in this patented claim, only do not adopt an arm reflected light path of spatial light modulator (SLM) to carry out photon collection beam split owing to consider the characteristics of random measurement matrix, and the algorithm reconstruction quality that is adopted is poor; Operand is big; Remain on the principle in certain technical defective, the present invention takes into full account single photon spectrum counting imaging system and the method that relation between the technical characterictic proposes a kind of complementary measurement in order to overcome above-mentioned technological deficiency, adopts the both arms complementary measurement; Visible light and near infrared light are measured simultaneously; Improved principle and algorithm, and proposed the spectrum map generalization method of wavelength-luminous power, to solve above-mentioned a series of problem.

Light spectrum image-forming is the important technology that obtains and show accurate colouring information, and one of reason is that spectrum picture has comprised spectral information, and former two is that the light spectrum image-forming technology has overcome the metamerism phenomenon well therefore.Light spectrum image-forming to utmost point low light level object has wide practical use in multiple field especially.

The photon counting imaging is exactly a kind of utmost point weak light detection technology, and through being recorded as the photon counting of image position, counting is equivalent to intensity signal, so obtain the space distribution situation of light intensity, adds up piece image at last.

Existing imaging spectral technology must be with any one dimension in one dimension spectrum, the two-dimensional image; Mode with sub-scanning realizes; Because the poor stability of nanometer displacement scanning platform, scanning process complicacy; Not only increase manufacturing cost, also greatly prolonged the test duration of object under test, for some biological sample, can be lowered into power.The drawback of bringing like this is the sampling time must reserve sufficient space to scanning.If when one dimension spectrum is realized with the scanning form, must adopt bin detector (the photosensitive detecting element by a large amount of is formed) to survey, like ICCD, EMCCD, APDs etc.The bin detector certain hour (integral time) that when the utmost point low light level is surveyed, need make public; On average the luminous flux to the unit picture element is minimum, adds the influence of dark counts, and signal to noise ratio (S/N ratio) is relatively poor; Extremely difficult accurately the reckoning dropped on the light intensity value on this pixel, has the problem of sensitivity.Wherein ICCD, EMCCD are known as and can accomplish single photon detection; But need degree of depth semiconductor refrigerating, cost is expensive, and the ICCD spatial resolution is relatively poor; And the EMCCD spatial resolution is good slightly, and the common issue with of existence all is to be difficult under the low light level noise of instrument is controlled or linear output; And APDs can be operated in Geiger mode angular position digitizer, but still is in conceptual phase, and high-precision APD array is difficult to make and flow; The APD array that externally announce in the Lincoln laboratory also only has 64 * 256 pixels, and to China's embargo, and present APD array wavelength response range is very limited; Only in visual wave band reach the quantum efficiency peak value; Because each pixel is all minimum, the necessary mean allocation of luminous flux is on whole array, and the influence of shot noise will become very significantly so.

Said compression sensing (Compressive Sensing; Abbreviation CS) theory is a brand-new mathematical theory that is proposed by people such as Donoho, Candes and Tao; Realization comes restoring signal ideally with the mode of stochastic sampling, still less data sampling number (far below the limit of Nyquist/Shannon's sampling theorem), and has more high robust.This principle elder generation compression sampling; Measured signal is sampled to low dimension mapping and to it by higher-dimension; Choose suitable sparse transformation framework Ψ; Make that x is sparse through Ψ conversion gained vector

; According to observation data y, measurement matrix A and framework Ψ, find the solution and be finally inversed by x by

at last then.

Said spatial light modulator (Spatial Light Modulator; Be called for short SLM) be that one type of ability loads on information on the optical data field of one dimension or bidimensional; Under the control of time dependent electric drive signal or other signal; The real-time optical information processing device that can modulate photodistributed intensity on the space; Can the light of the angle incident of stipulating by spatial light modulator be reflexed to both direction with certain probability, generally adopt two-value to characterize the state of reflection direction, common spatial light modulator has DMD, liquid crystal light valve, frosted glass etc.Wherein, DMD (Digital Micro-mirror Device is called for short DMD) is the most accurate in the world photoswitch.The core of DMD is installed in the micro mirror array that the micro-reflector on the hinge forms (DMD of main flow is by 1024 * 768 array formation by thousands of; Maximum can be to 2048 * 1152), each eyeglass is of a size of 14 μ m * 14 μ m (or 16 μ m * 16 μ m) and light that can a pixel of break-make, and these micro mirrors are all suspending; Through the storage unit under each eyeglass is all carried out electronic addressing with the scale-of-two planed signal; Just can let each eyeglass with electrostatic means to two tilt, be designated as 1 and 0 to this two states, respectively corresponding " opening " and " pass "; When eyeglass was not worked, they were in " berthing " state of 0 °.

How to realize high-quality image-forming spectral measurement to utmost point low light level object; How to evade the restriction of mechanical scanning to imaging resolution; How to reduce dimension and the measurement scale measured, this proposes new challenge to imaging spectral, and the present invention remedies the defective of prior art on signal to noise ratio (S/N ratio) with high flux; Survey the observation that realizes visible light and near infrared light with both arms, utilization compression sensing theory improves image quality and reduces the measurement scale.

Summary of the invention

The objective of the invention is to; For realizing that the spectral component of observed objects visible light and near infrared light is carried out evaluating objects simultaneously; Solve dimension scanning that conventional spectrum imaging method exists, rebuild low precision, to problems such as the utmost point low light level are insensitive, thereby a kind of single photon spectrum counting imaging system and method for complementary measurement are provided.

The present invention is the basis with compression sensing theory; With visible light single-photon detector linear array and near infrared light single-photon detector linear array as detecting element; Adopt reflected light collection simultaneously, beam split, the detection of complementary measurement technology and spectrum light splitting technology with spatial light modulator two arms; Utilize compression sensing thought to rebuild then, recover the coloured image of visible light and near infrared light, the line correlation spectral analysis of going forward side by side.

For realizing above-mentioned purpose, the invention provides a kind of single photon spectrum counting imaging system of complementary measurement, it is characterized in that said system comprises:

Optical imagery parts, spatial light modulator, first group of receipts optical alignment parts, second group of receipts optical alignment parts, first group of spectrum light splitting part, second group of spectrum light splitting part, visible light single-photon detector linear array, near infrared light single-photon detector linear array, hyperchannel counter and information process unit; Wherein, the light that carries object under test information is imaged on the said spatial light modulator through said optical imagery parts, and the emergent light after the optical modulation at random of said spatial light modulator is divided into the transmission of two arm directions;

Receive optical alignment parts, first group of spectrum light splitting part and visible light single-photon detector linear array and be arranged at the first arm direction for said first group, be used to survey the photon of visible light, export some group pulse waveforms; Receive optical alignment parts, second group of spectrum light splitting part and near infrared light single-photon detector linear array and be arranged at the second arm direction for said second group, be used to survey the photon of near infrared light spectrum, export some group pulse waveforms;

Said hyperchannel counter is arranged at via on the circuit after said visible light single-photon detector linear array and the near infrared light single-photon detector linear array, is used for the pulse waveform under each passage is carried out filtering, discriminating and stored count;

Said information process unit is according to the pairing wavelength information of each counting channel on the complementary matrix on the said spatial light modulator, each count value and the hyperchannel counter on the hyperchannel counter; The related compression sensing algorithm of utilization reconstructs the coloured image of visible light and near infrared light, and can further analyze the composition under the specific wavelength.

In the technique scheme; Described visible light single-photon detector linear array and near infrared light single-photon detector linear array are operated in the linear array that the single photon point probe under the Geiger mode angular position digitizer is formed by several corresponding different wave lengths; Select the single photon point detecting element of several corresponding different wave lengths respectively to visible light wave range and near infrared light wave band, many group optical filters of can arranging in pairs or groups use;

Said visible light single-photon detector linear array and near infrared light single-photon detector linear array position be double replacement mutually;

The detection mode of said visible light single-photon detector linear array and near infrared light single-photon detector linear array adopts fiber optic collimator or Free-space coupling;

Wherein, visible light single-photon detector linear array and near infrared light single-photon detector linear array also can enable certain delegation or the acquisition of a certain row by the avalanche diode array.

In the technique scheme, the every conversion of the stochastic matrix on spatial light modulator once, said hyperchannel counter records is once counted, some batch total numerical value of its output are as the measured value in the compression sensing algorithm that information process unit adopted.

In the technique scheme, described first group of spectrum light splitting part and second group of spectrum light splitting part include: optical alignment part, beam split part, measurement of angle part, photometric observation and measure portion; Light absorbing part spare partly is used with said optical alignment, is used for the emergent light on a certain arm direction on the spatial light modulator is all collected and preliminary collimation.

Optimize; When utmost point low light level light intensity exceeds the investigative range of said visible light single-photon detector linear array or near infrared light single-photon detector linear array; On any light path position before said visible light single-photon detector linear array or near infrared light single-photon detector linear array attenuator is set, is used for light decay is reduced to the investigative range of said single-photon detector linear array.

Also provide a kind of single photon spectrum of complementary measurement to count formation method based on said system the present invention, said method comprises:

Step 101) light that carries object under test information is imaged on the spatial light modulator through the optical imagery parts, and through the optical modulation at random of said spatial light modulator, emergent light is divided into two arm directions with certain probability;

Step 102) respectively light beam is carried out beam split in two arm exit directions and collect, be collected in visible light single-photon detector linear array and the near infrared light single-photon detector linear array, be recorded in the hyperchannel counter with the photon counting form with assembling;

Step 103) rebuilds or the correlation spectrum analysis through the coloured image of compression sensing algorithm realization visible light and near infrared light, accomplish the single photon spectrum counting imaging of complementary measurement.

In the technique scheme, said step 103) further comprise:

Step 103-1), the step that is used for compression sampling:

By spatial light modulator the light that is incident on it is carried out optical modulation at random; Make the two-way emergent light invest follow-up receipts optical alignment parts and single-photon detector linear array with certain probability respectively; The every conversion of random array on the spatial light modulator once; Measure and note the pairing total photon number of some specific wavelengths on two bands simultaneously, be equivalent to the light intensity of some points on the measuring light bands of a spectrum, measure M time; M is much smaller than measured signal dimension N, to accomplish measured signal compression sampling in visible light wave range and near infrared light wave band;

Wherein, Said spatial light modulator is meant under the control of time dependent signal; The real-time optical information processing device that can modulate photodistributed intensity on the space; Can the light by the angle incident of spatial light modulator regulation be reflexed to both direction with certain probability, what said optical modulation at random was meant modulation matrix on the spatial light modulator is very at random, and this matrix adopts two-value to characterize the state of reflection direction;

Step 103-2), the step that is used for sparse reconstruction:

Total photon number that visible light single-photon detector linear array and near infrared light single-photon detector linear array are detected in twice transfer interval of spatial light modulator random array is as two groups of measured value y _iAnd y ' _i, the corresponding stochastic matrix a of difference _iBenefit a ' with matrix _i, because matrix element is with 0 and 1 two value representations, the benefit of matrix is I-a, wherein I is a unit matrix;

With a _iAnd a ' _iBe stretched to delegation respectively, respectively as visible light measure matrix A and near infrared light measurement matrix A ' in i capable, measure M time; Measure matrix all to amount to M capable for two; If visible light single-photon detector linear array has P point, near infrared light single-photon detector linear array has Q point, and then the measured value of two arms has P group and Q group respectively; Every group all amounts to the M dimension; If each specifically chooses some groups of data two arms,, utilize related compression sensing reconstruction algorithm to rebuild the coloured image of object of observation at visible light wave range and near infrared light wave band more than or equal to three groups; Wherein the coloured image of near infrared light wave band is that mark comes out, and promptly chooses three kinds of infrared wavelengths from big to small by wavelength and is designated red green blue tricolor; Get one group of data and just can carry out the constituent analysis of this wavelength if appoint.

In the technique scheme, the counting of each passage is added up, photon counting is converted into luminous power,, just can count the spectrogram of a wavelength-luminous power, and then obtain the characteristic peak of observed objects in conjunction with the pairing wavelength information of each passage.

In the technique scheme, the mathematical model of said compression sensing is following:

Each gets a specific wavelength in visible-range and near infrared range, and the signal under this two wavelength is stretched to row: Then sampling process can be regarded two groups as and measures the process that matrixes and two specific wavelength signals are made inner product, obtains two groups of observation vector y respectively _Pi, y ' _Qi, i=1,2 ..., M, p=1,2 ..., P, q=1,2 ..., Q, wherein

(K<m＜＜N),

Be system noise, if but x is compressible or sparse expression, then

Ψ=[ψ wherein ₁, ψ ₂..., ψ _N] be sparse transformation matrix,

Be related degree of rarefication, so, the process of compression sampling can be described as following formula:

$[y_p,y_q^{\&prime;}]=[\mathrm{A\&Psi;}{\stackrel{\&OverBar;}{x}}_p+e,A^{\&prime;}\mathrm{\&Psi;}{\stackrel{\&OverBar;}{x}}_q^{\&prime;}+e^{\&prime;}]$

Wherein, A is set to two-value random measurement matrix;

Described sparse reconstruction is at known observation data y _p, y ' _qWith the measurement matrix A, find the solution x under the condition of A ' _p, x ' _q, to find the solution with the strategy of compression sensing, specific algorithm is described as following formula:

$\underset{{\stackrel{\&OverBar;}{x}}_p}{\min }\frac{1}{2}{\left|\right|y_p-\mathrm{A\&Psi;}{\stackrel{\&OverBar;}{x}}_p\left|\right|}_2^2+\mathrm{\&tau;}{\left|\right|{\stackrel{\&OverBar;}{x}}_p\left|\right|}_1,\underset{{\stackrel{\&OverBar;}{x}}_q^{\&prime;}}{\min }\frac{1}{2}{\left|\right|y_q^{\&prime;}-A^{\&prime;}\mathrm{\&Psi;}{\stackrel{\&OverBar;}{x}}_q^{\&prime;}\left|\right|}_2^2+\mathrm{\&tau;}{\left|\right|{\stackrel{\&OverBar;}{x}}_q^{\&prime;}\left|\right|}_1$

Wherein, || ... || _lRepresent the norm operator, Only need the inferior measurement of M≤O (Klog (N/K)), just can be finally inversed by the light intensity space distribution information x of object under test under visible light wave range and two specific wavelengths of near infrared light wave band _pAnd x ' _q, if specifically choose 3 groups of measurement data separately, reuse above-mentioned model at visible light and near infrared light wave band, adopt the three primary colors principle just can reconstruct the coloured image of visible light wave range and near infrared light wave band.

In the technique scheme; The compression sensing algorithm of described association is based on two measurement matrixes that satisfy complementary relationship; The core algorithm strategy is regarded unit matrix as the measurement matrix and is participated in computing; Said core algorithm based on the compression sensing algorithm, add corrected parameter after the computing, the income value after the correcting process again with x _pDo match operation, just obtain x ' _q, make visible light signal x _pWith near infrared light signal x ' _qCan obtain simultaneously.

Compared with prior art the invention has the advantages that: the present invention is theoretical with the compression sensing, complementary measurement is technological and the spectrum light splitting technology is the basis; Through spatial light modulator optical modulation at random, as detecting element, carry out both arms and survey with visible light single-photon detector linear array and near infrared light single-photon detector linear array; Realized obtaining three-dimensional information parameters such as space two-dimensional, spectrum dimension with linear array sampling dimension; Greatly save and survey dimension, can measure simultaneously, can obtain more spectral information utmost point low light level visible light information and near infrared light information; Can carry out the object constituent analysis to any interested wavelength; Help to advance the fast development of association area, sensitivity can reach the single photon level, and resolution is high.Adopt the mode of complementary measurement, can dwindle calculated amount, the utilization of improved related compression sensing algorithm is measured the characteristics raising algorithm of Matrix Complementarity and is rebuild precision, and can the bigger image of calculating pixel.The present invention has expanded the near infrared light investigative range on existing basis, and visible light with near infrared light detection can carry out simultaneously, scientific research field has broad prospect of application in special forward position; Need not scanning, directly linear array imaging does not have mechanical vibration effect; Luminous flux is high; Signal to noise ratio (S/N ratio) is high, and the wavelength wide coverage has solved the contradiction between the supply and demand of spectrum field.

Based on above advantage and innovative point, the present invention can be widely used in fields such as light spectrum image-forming Measurement and analysis, biotic component detection, astronomical sight, night vision observation, utmost point weak light detection, concentration detection, imaging of medical, military and national defense, monitoring, remotely sensed image, ghost imaging.

Description of drawings

Fig. 1 is the structural representation of the single photon spectrum counting imaging system of complementary measurement of the present invention;

Fig. 2 is the simulated experiment result of the embodiment of the invention, and M17SWex nebula visible images red green blue tricolor decomposes and image reconstruction; Wherein, (a) be the R of M17SWex nebula visible light original image divide spirogram, (b) be the G of M17SWex nebula visible light original image to divide spirogram, (c) be that the B of M17SWex nebula visible light original image divides spirogram, (d) be the colour original of M17SWex nebula visible light original image; (e) being that reconstruction figure, (f) of visible light R component is that reconstruction figure, (g) of visible light G component is the reconstruction figure of visible light B component, (h) is the visible light cromogram that is finally inversed by according to the RGB three-component;

Fig. 3 is the simulated experiment result of the embodiment of the invention, and M17SWex nebula infrared light image red green blue tricolor decomposes and image reconstruction; Wherein, (a) and (b), (c), (d) are respectively R, G, B component and the colour originals of M17SWex nebula infrared light original image; (e), (f), (g) be respectively the reconstruction figure of infrared light R, G, B component, (h) is the infrared light cromogram that is finally inversed by according to this three-component.

The accompanying drawing sign

1, optical imagery parts 2, spatial light modulator

3, receive optical alignment parts 4, second group and receive the optical alignment parts for first group

5, first group of spectrum light splitting part 6, second group of spectrum light splitting part

7, visible light single-photon detector linear array 8, near infrared light single-photon detector linear array

9, hyperchannel counter

Embodiment

Below in conjunction with accompanying drawing the present invention is done further detailed description.

The single photon spectrum counting imaging system of a kind of complementary measurement that the present invention proposes; It is characterized in that; The single photon spectrum of this complementary measurement counting imaging system adopts that the compression sensing is theoretical, complementary measurement is technological and the spectrum light splitting technology, and with visible light single-photon detector linear array and near infrared light single-photon detector linear array as detecting element, the multispectral picture that is counted as of single photon; The coloured image of output visible light and near infrared light, and can carry out the correlation spectrum analysis;

The single photon spectrum counting imaging system of described complementary measurement comprises: optical imagery parts, spatial light modulator, two receipts optical alignment parts, two spectrum light splitting parts, visible light single-photon detector linear array, near infrared light single-photon detector linear array and hyperchannel counters;

Wherein, The light that carries object under test information is imaged on the spatial light modulator (SLM) through the optical imagery parts, and through the optical modulation at random of spatial light modulator, emergent light is divided into two arm directions with certain probability; Respectively the light on two arms is collimated and the spectrum beam split earlier; One arm is got visible light, and an arm is got near infrared light spectrum, collects visible light single-photon detector linear array and near infrared light single-photon detector linear array respectively; And be recorded in several passages in the hyperchannel counter with the counting form; Last according to many batch totals numerical value on the complementary matrix on the spatial light modulator, the hyperchannel counter and the pairing wavelength information of passage, the related compression sensing algorithm of utilization can reconstruct the coloured image of visible light and near infrared light, and can further analyze the composition under the specific wavelength.

Described single-photon detector linear array is operated in the linear array that the single photon point probe under the Geiger mode angular position digitizer is formed by several corresponding different wave lengths; Possesses the single photon resolution characteristic; Select the single photon point detecting element of several corresponding different wave lengths respectively at visible light wave range and near infrared light wave band, many group optical filters of can arranging in pairs or groups use, in linear array of composition of visible-range; Another linear array of the composition of near infrared range; Be separately positioned on two arm exit directions of spatial light modulator, but both position phase double replacements, and detection mode can adopt fiber optic collimator or Free-space coupling; Said single-photon detector linear array also can enable certain delegation or the acquisition of a certain row by avalanche diode (APD) array.

Described single-photon detector linear array need cooperate the hyperchannel counter to use; The single-photon detector linear array is used for detection of photons; Export some group pulse waveforms, the hyperchannel counter is used for the pulse waveform under each passage is carried out filtering, discriminating and stored count, and the every conversion of the stochastic matrix on the spatial light modulator once; Record is counting once, and some batch total numerical value of its output are as the measured value in the compression sensing algorithm.

Described spectrum light splitting part comprises: optical alignment part, beam split part, measurement of angle part, photometric observation and measure portion, be used for spectrum beam split and Measurement and analysis, and generally adopt prismatic decomposition or grating beam splitting; Receive the optical alignment parts and cooperate it to use, be used for the emergent light on a certain arm direction on the spatial light modulator is all collected and preliminary collimation.

Optional; When utmost point low light level light intensity exceeds the investigative range of single-photon detector linear array; Need on any light path position before the single-photon detector linear array suitable attenuator to be set; Utmost point low light level light intensity is used for light decay is reduced to the investigative range of single-photon detector linear array, if in the investigative range of single-photon detector linear array, then need not to be provided with attenuator again.

The present invention also proposes a kind of single photon spectrum counting formation method of complementary measurement; It is characterized in that; This method has adopted compression sensing theory, complementary measurement is technological and the spectrum light splitting technology; Respectively light beam is carried out beam split in spatial light modulator two arm exit directions and collect, be collected in visible light single-photon detector linear array and the near infrared light single-photon detector linear array, be recorded in the hyperchannel counter with the photon counting form with assembling; Coloured image through compression sensing algorithm realization visible light and near infrared light is rebuild and the correlation spectrum analysis, and said method comprises following steps:

Step 1 is used for the step of compression sampling:

By spatial light modulator the light that is incident on it is carried out optical modulation at random; Make the two-way emergent light invest follow-up receipts optical alignment parts and single-photon detector linear array with certain probability respectively; The every conversion of random array on the spatial light modulator once; Measure and note the pairing total photon number of some specific wavelengths on two bands simultaneously, be equivalent to the light intensity of some points on the measuring light bands of a spectrum, measure M time; M is much smaller than measured signal dimension N, to accomplish measured signal compression sampling in visible light wave range and near infrared light wave band;

Said spatial light modulator is meant under the control of time dependent electric drive signal or other signal; The real-time optical information processing device that can modulate photodistributed intensity on the space; Light by the angle incident of spatial light modulator regulation can be reflexed to both direction with certain probability; Its direction also needs not be certain fixed angle; Can be limited in the certain angle scope; What said light modulation at random was meant modulation matrix on the spatial light modulator is very at random; The general state that adopts two-value to characterize reflection direction, common spatial light modulator has DMD (DMD); Liquid crystal light valve; Frosted glass etc.;

Step 2 is used for the step of sparse reconstruction:

Total photon number that visible light single-photon detector linear array and near infrared light single-photon detector linear array are detected in twice transfer interval of spatial light modulator random array is as two groups of measured value y _iAnd y ' _i, the corresponding stochastic matrix a of difference _iBenefit a ' with matrix _i, because matrix element is with 0 and 1 two value representations, the benefit of matrix is I-a, wherein I is a unit matrix, with a _iAnd a ' _iBe stretched to delegation respectively; Respectively as visible light measure matrix A and near infrared light measure matrix A ' in i capable, measure M time, it is capable that two measurement matrixes all amount to M; If visible light single-photon detector linear array has P point; Near infrared light single-photon detector linear array has Q point, and then the measured value of two arms has P group and Q group respectively, and every group all amounts to the M dimension; If each specifically chooses 3 groups of data two arms; Utilize related compression sensing reconstruction algorithm just can reconstruct the coloured image of object of observation at visible light wave range and near infrared light wave band, wherein the coloured image of near infrared light wave band is that mark comes out, and promptly chooses three kinds of infrared wavelengths from big to small by wavelength and is designated red green blue tricolor; Get one group of data and just can carry out the constituent analysis of this wavelength if appoint.

The counting of each passage is added up, photon counting is converted into luminous power,, just can count the spectrogram of a wavelength-luminous power, and then obtain the characteristic peak of observed objects in conjunction with the pairing wavelength information of each passage.

Its mathematical model is following:

Each gets a specific wavelength in visible-range and near infrared range, and the signal under this two wavelength is stretched to row:

Then sampling process can be regarded two groups as and measures the process that matrixes and two specific wavelength signals are made inner product, obtains two groups of observation vector y respectively _Pi, y ' _Qi, i=1,2 ..., M, p=1,2 ..., P, q=1,2 ..., Q, wherein

(K<m＜＜N),

Be system noise, if but x is compressible or sparse expression, then

Ψ=[ψ wherein ₁, ψ ₂..., ψ _N] be sparse transformation matrix (being sparse framework), Be related degree of rarefication, so, the process of compression sampling can be described as following formula:

$[y_p,y_q^{\&prime;}]=[\mathrm{A\&Psi;}{\stackrel{\&OverBar;}{x}}_p+e,A^{\&prime;}\mathrm{\&Psi;}{\stackrel{\&OverBar;}{x}}_q^{\&prime;}+e^{\&prime;}]$

A Ψ wherein, A ' Ψ all need satisfy Restricted Isometry Property (RIP), and A, A ' and Ψ need uncorrelated, because A, A ' complementation for satisfying above-mentioned condition, only needs A be set to two-value random measurement matrix among the present invention;

Described sparse reconstruction is at known observation data y _p, y ' _qWith the measurement matrix A, find the solution x under the condition of A ' _p, x ' _q, this is a NP-hard problem, but is converted into l1 norm or l2 norm problem, and the thought of just available compression sensing is found the solution, and algorithm can divide the numerous species type, as example, gets wherein a kind of common form of presentation, is described as following formula:

$\underset{{\stackrel{\&OverBar;}{x}}_p}{\min }\frac{1}{2}{\left|\right|y_p-\mathrm{A\&Psi;}{\stackrel{\&OverBar;}{x}}_p\left|\right|}_2^2+\mathrm{\&tau;}{\left|\right|{\stackrel{\&OverBar;}{x}}_p\left|\right|}_1,\underset{{\stackrel{\&OverBar;}{x}}_q^{\&prime;}}{\min }\frac{1}{2}{\left|\right|y_q^{\&prime;}-A^{\&prime;}\mathrm{\&Psi;}{\stackrel{\&OverBar;}{x}}_q^{\&prime;}\left|\right|}_2^2+\mathrm{\&tau;}{\left|\right|{\stackrel{\&OverBar;}{x}}_q^{\&prime;}\left|\right|}_1$

Wherein || ... || _lRepresent the norm operator,

Only need the inferior measurement of M≤O (Klog (N/K)), just can be finally inversed by the light intensity space distribution information x of object under test under visible light wave range and two specific wavelengths of near infrared light wave band _pAnd x ' _q, if specifically choose 3 groups of measurement data separately, reuse above-mentioned model at visible light and near infrared light wave band, adopt the three primary colors principle just can reconstruct the coloured image of visible light wave range and near infrared light wave band.

Optional, said compression sensing algorithm comprises: greedy reconstruction algorithm, coupling track algorithm MP, quadrature coupling track algorithm OMP, basic track algorithm BP, LASSO, LARS, GPSR, Bayesian Estimation algorithm, magic, IST, TV, StOMP, CoSaMP, LBI, SP, l1_ls, smp algorithm, SpaRSA algorithm, TwIST algorithm, l ₀Reconstruction algorithm, l ₁Reconstruction algorithm, l ₂Reconstruction algorithm etc.; The core concept of algorithm communicates, and is alternately to minimize and upgrade multiplier, on the skill of calculating, can slightly have any different, be that example is done the explanation of algorithm core concept with the TV algorithm:

The TV model is:

S.t.Au=b is equivalent to S.t.Au=b and D _iU=w _iCorresponding augmentation lagrange problem is:

$\underset{w_i,u}{\min }\underset{i}{\mathrm{\&Sigma;}}({\left|\right|w_i\left|\right|}_2-v_i^T(D_{i}u-w_i)+\frac{\mathrm{\&beta;}}{2}{\left|\right|D_{i}u-w_i\left|\right|}_2^2)-{\mathrm{\&lambda;}}^T(\mathrm{Au}-b)+\frac{\mathrm{\&mu;}}{2}{\left|\right|\mathrm{Au}-b\left|\right|}_2^2$

Input b, A, μ, β>0, initialization u=b;

When not restraining, minimize augmentation Lagrange power function through next being similar to of alternating direction scheme (alternating direction scheme), and bring in constant renewal in multiplier, promptly repeat following three steps and operate:

Fixedly u is constant for step (1), is calculated as follows w

$w_i=\max \{{\left|\right|D_{i}u-v_i/\mathrm{\&beta;}\left|\right|}_2-\frac{1}{\mathrm{\&beta;}},0\}\frac{D_{i}u-v_i/\mathrm{\&beta;}}{{\left|\right|D_{i}u-v_i/\mathrm{\&beta;}\left|\right|}_2}$

Fixedly w is constant for step (2), is calculated as follows u

$u=F^{-1}\left(\frac{F\left(D^{\left(1\right)}\right)*\mathrm{oF}\left(w_1\right)+F{\left(D^{\left(2\right)}\right)}^{*}\mathrm{oF}\left(w_2\right)+(\mathrm{\&mu;}/\mathrm{\&beta;})F{\left(A\right)}^{*}\mathrm{oF}\left(b\right)}{F\left(D^{\left(1\right)}\right)*\mathrm{oF}\left(D^{\left(1\right)}\right)+F{\left(D^{\left(2\right)}\right)}^{*}\mathrm{oF}\left(D^{\left(2\right)}\right)+(\mathrm{\&mu;}/\mathrm{\&beta;})F{\left(A\right)}^{*}\mathrm{oF}\left(A\right)}\right)$

Wherein, D ⁽¹⁾And D ⁽²⁾Be respectively single order finite matrix level difference and vertical differentiation, F is a two dimensional discrete Fourier transform, ^*The expression complex conjugate, o representes that number takes advantage of;

Step (3) is upgraded multiplier: $v_i\&LeftArrow;v_i-\mathrm{\&beta;}(D_i\hat{u}-{\hat{w}}_i),$ $\mathrm{\&lambda;}\&LeftArrow;\mathrm{\&lambda;}-\mathrm{\&mu;}(A\hat{u}-b).$

The compression sensing algorithm of described association is based on two, and to measure matrixes be complementary and propose, and core algorithm thought is unit matrix regarded as and measures matrix and participate in computing, on the basis of described algorithm thought, adds corrected parameter, income value again with x _pDo match operation, just obtain x ' _q, storage space is dwindled in very big easy computing, visible light signal x _pWith near infrared light signal x ' _qCan obtain simultaneously.

As shown in Figure 1, the utmost point low light level that carries observed objects information is imaged on the spatial light modulator 2 through optical imagery parts 1.Spatial light modulator can carry out optical modulation at random to incident light; Make it with certain probability outgoing to two arm direction; On this two arms exit direction, be provided with first group respectively and receive optical alignment parts 3 and second group of receipts optical alignment parts 4, first group of spectrum light splitting part 5, second group of spectrum light splitting part 6, visible light single-photon detector linear array 7 and near infrared light single-photon detector linear array 8; Receiving the optical alignment parts for two groups is used for the reflected light of two arms is collected and preliminary collimation; Two groups of spectrum light splitting parts are with the further collimation of the light of two arms, and then the branch spectral measurement, are incident upon on the single-photon detector linear array.What need explanation is that the position of visible light single-photon detector linear array 7 and near infrared light single-photon detector linear array 8 is replaceable.The pulse waveform of single-photon detector linear array output is input in some counting channels of hyperchannel counter 9, carries out filtering, discriminating and stored count respectively.Last information process unit is according to many groups measured value on several counting channels of the complementary matrix on the spatial light modulator 2, hyperchannel counter 9 and the pairing wavelength information of each passage; Just can recover the coloured image of visible light and near infrared light respectively; And can carry out the composition distributional analysis to interested wavelength; Spectrogram that can also output wavelength-luminous power, and then obtain the characteristic peak of observed objects.

Need to prove; When utmost point low light level light intensity exceeds the investigative range of visible light single-photon detector linear array 7 and near infrared light single-photon detector linear array 8; Need on any light path position before the single-photon detector linear array suitable attenuator to be set; Utmost point low light level light intensity is used for light decay is reduced to the investigative range of single-photon detector linear array, if in the investigative range of single-photon detector linear array, then need not to be provided with attenuator again.

Feasibility and practicality for checking native system algorithm; Visible images and the infrared light image of in simulated experiment, choosing the M17SWex nebula carry out R, G, the decomposition of B three primary colors; Come the light signal under each wavelength channel of simulated spectra, be multiplied by corresponding two-value random measurement matrix respectively, the measurement Matrix Complementarity that wherein visible light and infrared light image adopted; Income value reloads additive white noise; Count measurement value under each wavelength channel that obtains simulating does not know to adopt under the situation of original image method proposed by the invention to rebuild in hypothesis, recover the coloured image of visible light and infrared light.The resolution of all images is 300 * 600 in the experiment; Adopt the TV algorithm to carry out image reconstruction; Obtain Fig. 2, result shown in Figure 3, wherein, Fig. 2 (a), Fig. 2 (b), Fig. 2 (c), Fig. 2 (d) are respectively R, G, B component and the colour originals of M17SWex nebula visible light original image; Fig. 2 (e), Fig. 2 (f), Fig. 2 (g) are respectively the reconstruction figure of visible light R, G, B component, and Fig. 2 (h) is the visible light cromogram that is finally inversed by according to this three-component; Fig. 3 (a), Fig. 3 (b), Fig. 3 (c), Fig. 3 (d) are respectively R, G, B component and the colour originals of M17SWex nebula infrared light original image; Fig. 3 (e), Fig. 3 (f), Fig. 3 (g) are respectively the reconstruction figure of infrared light R, G, B component, and Fig. 3 (h) is the infrared light cromogram that is finally inversed by according to this three-component; See that from image quality reconstruction coloured picture and former coloured picture difference are extremely low, thereby image quality is high, application prospect is extensive.

Need to prove that the former figure of M17SWex visible light nebula is from the Digitized Sky Survey (Digitized Sky Survey is called for short DSS) of Britain's Schmidt telescope; The former figure of M17SWex infrared light nebula is from the Spitzer space telescope; In infrared light image, we can clearly see that a dust cloud that seems imperial shape outwards flies out from once bright blast, but in visible images; This part dust cloud shrouds fully in shade, can't differentiate.This imperial shape dust cloud that infrared light image demonstrates is known as M17SWex, probably is the fixed star that is forming.These large-scale fixed stars have illuminated the nebula at the M17 of picture centre, also blown afloat one huge be positioned at the M17 left hand edge constitute " foam " by luminous gas and dust.The gentle Galactic System of passing the Sagittarius spiral arm just from right to left that is embodied in of this regional fixed star has caused " domino effect " of the milky way.The SWex dragon shape nebula of M17 is hidden in the opaque dust cloud under visible light.Be hidden in the zone under " black clouds " and just can capture this, thereby disclose the situation that fixed star forms commitment with infrared ray.Infrared light is sightless in fact, does not have color, and the color sign among the figure is come out, and adopts the three primary colors principle equally, the light of red sign 24000nm, the light of green sign 8000nm, the light of blue sign 3600nm.If testing data is a near infrared light, principle is the same.Can find out that from this embodiment the present invention has very great help to disclosing the astrophysics phenomenon, will in astronomical sight, ride on the crest of success.Embodiments of the invention not and be confined to this all will not have good application at other like forward position scientific research fields such as light spectrum image-forming Measurement and analysis, biotic component detection, night vision observation, utmost point weak light detection, concentration detection, imaging of medical, military and national defense, monitoring, remotely sensed image, ghost imagings.

Need to prove that at last algorithm described in the embodiment through a large amount of experimental data checkings, has been true and reliable, collocation hardware just can be realized technical scheme of the present invention.Said all embodiment are merely the present invention are further elaborated, and are not absolute, but respective extension.Those of ordinary skill in the art should be appreciated that technical scheme of the present invention is made amendment, adds, deletes or be equal to replacement that do not break away from the spirit and the scope of technical scheme of the present invention, it all should be encompassed in the middle of the claim scope of the present invention.

Claims (10)

1. the single photon spectrum of a complementary measurement is counted imaging system, it is characterized in that said system comprises:

Optical imagery parts, spatial light modulator, first group of receipts optical alignment parts, second group of receipts optical alignment parts, first group of spectrum light splitting part, second group of spectrum light splitting part, visible light single-photon detector linear array, near infrared light single-photon detector linear array, hyperchannel counter and information process unit; Wherein, the light that carries object under test information is imaged on the said spatial light modulator through said optical imagery parts, and the emergent light after the optical modulation at random of said spatial light modulator is divided into the transmission of two arm directions;

Receive optical alignment parts, first group of spectrum light splitting part and visible light single-photon detector linear array and be arranged at the first arm direction for said first group, be used to survey the photon of visible light, export some group pulse waveforms; Receive optical alignment parts, second group of spectrum light splitting part and near infrared light single-photon detector linear array and be arranged at the second arm direction for said second group, be used to survey the photon of near infrared light spectrum, export some group pulse waveforms;

Said hyperchannel counter is arranged at via on the circuit after said visible light single-photon detector linear array and the near infrared light single-photon detector linear array, is used for the pulse waveform under each passage is carried out filtering, discriminating and stored count;

Said information process unit is according to the pairing wavelength information of each counting channel on the complementary matrix on the said spatial light modulator, each count value and the hyperchannel counter on the hyperchannel counter; The related compression sensing algorithm of utilization reconstructs the coloured image of visible light and near infrared light, and can further analyze the composition under the specific wavelength.

2. the single photon spectrum of complementary measurement according to claim 1 is counted imaging system; It is characterized in that; Described visible light single-photon detector linear array and near infrared light single-photon detector linear array are operated in the linear array that the single photon point probe under the Geiger mode angular position digitizer is formed by several corresponding different wave lengths; Select the single photon point detecting element of several corresponding different wave lengths respectively to visible light wave range and near infrared light wave band, many group optical filters of can arranging in pairs or groups use;

Said visible light single-photon detector linear array and near infrared light single-photon detector linear array position be double replacement mutually;

The detection mode of said visible light single-photon detector linear array and near infrared light single-photon detector linear array adopts fiber optic collimator or Free-space coupling;

Wherein, visible light single-photon detector linear array and near infrared light single-photon detector linear array also can enable certain delegation or the acquisition of a certain row by the avalanche diode array.

3. the single photon spectrum of complementary measurement according to claim 1 is counted imaging system; It is characterized in that; The every conversion of stochastic matrix on spatial light modulator once; Said hyperchannel counter records is once counted, and some batch total numerical value of its output are as the measured value in the compression sensing algorithm that information process unit adopted.

4. count imaging system based on the single photon spectrum of the described complementary measurement of claim 1; It is characterized in that described first group of spectrum light splitting part and second group of spectrum light splitting part include: optical alignment part, beam split part, angular surveying part, photometric observation and measure portion;

Light absorbing part spare partly is used with said optical alignment, is used for the emergent light on a certain arm direction on the spatial light modulator is all collected and preliminary collimation.

5. the single photon spectrum of complementary measurement according to claim 1 is counted imaging system; It is characterized in that; When utmost point low light level light intensity exceeds the investigative range of said visible light single-photon detector linear array or near infrared light single-photon detector linear array; On any light path position before said visible light single-photon detector linear array or near infrared light single-photon detector linear array attenuator is set, is used for light decay is reduced to the investigative range of said single-photon detector linear array.

6. the single photon spectrum of a complementary measurement is counted formation method, and said method comprises:

Step 101) light that carries object under test information is imaged on the spatial light modulator through the optical imagery parts, and through the optical modulation at random of said spatial light modulator, emergent light is divided into two arm directions with certain probability;

Step 102) respectively light beam is carried out beam split in two arm exit directions and collect, be collected in visible light single-photon detector linear array and the near infrared light single-photon detector linear array, be recorded in the hyperchannel counter with the photon counting form with assembling;

Step 103) rebuilds or the correlation spectrum analysis through the coloured image of compression sensing algorithm realization visible light and near infrared light, accomplish the single photon spectrum counting imaging of complementary measurement.

7. the single photon spectrum of complementary measurement according to claim 6 counting formation method is characterized in that said step 103) further comprise:

Step 103-1), the step that is used for compression sampling:

By spatial light modulator the light that is incident on it is carried out optical modulation at random; Make the two-way emergent light invest follow-up receipts optical alignment parts and single-photon detector linear array with certain probability respectively; The every conversion of random array on the spatial light modulator once; Measure and note the pairing total photon number of some specific wavelengths on two bands simultaneously, be equivalent to the light intensity of some points on the measuring light bands of a spectrum, measure M time; M is much smaller than measured signal dimension N, to accomplish measured signal compression sampling in visible light wave range and near infrared light wave band;

Wherein, Said spatial light modulator is meant under the control of time dependent signal; The real-time optical information processing device that can modulate photodistributed intensity on the space; Can the light by the angle incident of spatial light modulator regulation be reflexed to both direction with certain probability, what said optical modulation at random was meant modulation matrix on the spatial light modulator is very at random, and this matrix adopts two-value to characterize the state of reflection direction;

Step 103-2), the step that is used for sparse reconstruction:

Total photon number that visible light single-photon detector linear array and near infrared light single-photon detector linear array are detected in twice transfer interval of spatial light modulator random array is as two groups of measured value y _iAnd y ' _i, the corresponding stochastic matrix a of difference _iBenefit a ' with matrix _i, because matrix element is with 0 and 1 two value representations, the benefit of matrix is I-a, wherein I is a unit matrix;

With a _iAnd a ' _iBe stretched to delegation respectively, respectively as visible light measure matrix A and near infrared light measurement matrix A ' in i capable, measure M time; Measure matrix all to amount to M capable for two; If visible light single-photon detector linear array has P point, near infrared light single-photon detector linear array has Q point, and then the measured value of two arms has P group and Q group respectively; Every group all amounts to the M dimension; If each specifically chooses some groups of data two arms,, utilize related compression sensing reconstruction algorithm to rebuild the coloured image of object of observation at visible light wave range and near infrared light wave band more than or equal to three groups; Wherein the coloured image of near infrared light wave band is that mark comes out, and promptly chooses three kinds of infrared wavelengths from big to small by wavelength and is designated red green blue tricolor; Get one group of data and just can carry out the constituent analysis of this wavelength if appoint.

8. the single photon spectrum of complementary measurement according to claim 6 is counted formation method; It is characterized in that; The counting of each passage is added up, photon counting is converted into luminous power, in conjunction with the pairing wavelength information of each passage; Just can count the spectrogram of a wavelength-luminous power, and then obtain the characteristic peak of observed objects.

9. the single photon spectrum of complementary measurement according to claim 6 is counted formation method, it is characterized in that the mathematical model of said compression sensing is following:

Each gets a specific wavelength in visible-range and near infrared range, and the signal under this two wavelength is stretched to row:

Then sampling process can be regarded two groups as and measures the process that matrixes and two specific wavelength signals are made inner product, obtains two groups of observation vector y respectively _Pi, y ' _Qi, i=1,2 ..., M, p=1,2 ..., P, q=1,2 ..., Q, wherein

(K<m＜＜N),

Be system noise, if but x is compressible or sparse expression, then

Ψ=[ψ wherein ₁, ψ ₂..., ψ _N] be sparse transformation matrix,

Be related degree of rarefication, so, the process of compression sampling can be described as following formula:

$[y_p,y_q^{\&prime;}]=[\mathrm{A\&Psi;}{\stackrel{\&OverBar;}{x}}_p+e,A^{\&prime;}\mathrm{\&Psi;}{\stackrel{\&OverBar;}{x}}_q^{\&prime;}+e^{\&prime;}]$

Wherein, A is set to two-value random measurement matrix;

Described sparse reconstruction is at known observation data y _p, y ' _qWith the measurement matrix A, find the solution x under the condition of A ' _p, x ' _q, to find the solution with the strategy of compression sensing, specific algorithm is described as following formula:

$\underset{{\stackrel{\&OverBar;}{x}}_p}{\min }\frac{1}{2}{\left|\right|y_p-\mathrm{A\&Psi;}{\stackrel{\&OverBar;}{x}}_p\left|\right|}_2^2+\mathrm{\&tau;}{\left|\right|{\stackrel{\&OverBar;}{x}}_p\left|\right|}_1,\underset{{\stackrel{\&OverBar;}{x}}_q^{\&prime;}}{\min }\frac{1}{2}{\left|\right|y_q^{\&prime;}-A^{\&prime;}\mathrm{\&Psi;}{\stackrel{\&OverBar;}{x}}_q^{\&prime;}\left|\right|}_2^2+\mathrm{\&tau;}{\left|\right|{\stackrel{\&OverBar;}{x}}_q^{\&prime;}\left|\right|}_1$

Wherein, || ... || _lRepresent the norm operator,

Only need the inferior measurement of M≤O (Klog (N/K)), just can be finally inversed by the light intensity space distribution information x of object under test under visible light wave range and two specific wavelengths of near infrared light wave band _pAnd x ' _q, if specifically choose 3 groups of measurement data separately, reuse above-mentioned model at visible light and near infrared light wave band, adopt the three primary colors principle just can reconstruct the coloured image of visible light wave range and near infrared light wave band.

10. the single photon spectrum of complementary measurement according to claim 6 is counted formation method; It is characterized in that; The compression sensing algorithm of described association is based on two measurement matrixes that satisfy complementary relationship, and the core algorithm strategy is regarded unit matrix as the measurement matrix and participated in computing, and said core algorithm is based on the compression sensing algorithm; Add corrected parameter after the computing, the income value after the correcting process again with x _pDo match operation, just obtain x ' _q, make visible light signal x _pWith near infrared light signal x ' _qCan obtain simultaneously.

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