CN104977084A - Method for improving imaging spatial resolution and spectral resolution of acousto-optic turnable filter (AOTF) - Google Patents

Abstract

The invention relates to the field of the acousto-optic turnable filter (AOTF) spectral imaging technology and relates to a method for improving the imaging spatial resolution and the spectral resolution of an AOTF. An optimization algorithm is provided to approach to true value through repeated iteration. At a certain wavelength, the light intensity of each pixel imaged by a charge coupled device (CCD) is subtracted by the light intensity of an obtrusive light under the broadening effect of the spectrum and the diffraction angle so as to obtain the true value of the light intensity, wherein the true value is obtained through repeated iteration. Therefore, the final imaging spatial resolution and the spectral resolution are improved through the repeated iteration process of the data cube of two-dimensional images and one-dimensional spectrums obtained by the AOTF. The method comprises the steps of firstly, conducting the broadening measurement on the diffraction angle of the AOTF; secondly, conducting the broadening measurement on the diffraction spectrum of the AOTF, and obtaining the diffraction efficiency eta (xi+m, yj, lambda k, md lambda) based on the above two measurement results; thirdly, obtaining the light intensity I0 (xi, yj, lambda k) of a to-be-measured target at the pixel (xi, yj) of the CCD through the spectral imaging process of the AOTF; fourthly, conducting the repeated iteration operation according to a formula. The above method is mainly applied in the spectral imaging aspect.

Description

A kind of method improving AOTF imaging space resolution and spectral resolution

Technical field

The present invention relates to AOTF spectral imaging technology field, more specifically, relating to a kind of method improving AOTF imaging space resolution and spectral resolution, is a kind of method adopting successive ignition optimized algorithm raising AOTF spatial resolution and spectral resolution according to AOTF diffraction characteristics.

Background technology

Acousto-optic tunable filter (Acousto-optic tunable filter, AOTF), compared with traditional beam splitter, has that volume is little, tuned speed is fast, spectral range is wide, diffraction efficiency advantages of higher.In recent years, the concern of researcher is more and more received based on the imaging spectral technology of AOTF.Imaging spectrometer based on AOTF is applied in remote sensing, environmental monitoring, biomedicine and food inspection.And the height of the spatial resolution of AOTF imaging spectrum system and spectral resolution directly affects the quality of AOTF light spectrum image-forming performance.

Be the drift phenomenon of removal of images in existing AOTF imaging spectrum system, eliminate drift in the mode of AOTF exit facet many employings wedge and Prism compensation.The image shift phenomenon that after but the method only considered AOTF optical filtering, the dispersion of main peak centre wavelength brings, do not consider the rear spectrum secondary lobe of AOTF optical filtering and certain broadening, namely also there is the broadening of angle of diffraction and wavelength in AOTF diffraction, to AOTF be caused lower in the imaging space resolution of diffraction direction like this, and also derivative spectomstry resolution decline.

Summary of the invention

Owing to there is spectrum widening after diffraction and angle of diffraction broadening causes diffraction direction imaging space resolution to decline and spectral resolution declines in measuring for existing AOTF light spectrum image-forming, according to spectrum widening after diffraction and angle of diffraction broadening one-to-one relationship, a kind of optimized algorithm adopting successive ignition to go to approach true value is proposed, under certain wavelength, the light intensity that each picture dot of CCD imaging obtains is deducted the stray light due to spectrum and angle of diffraction broadening, thus obtain light intensity true value, this true value is through successive ignition and obtains, the two dimensional image obtained by AOTF because of the method and the data cube of one dimension spectrum improve final imaging space resolution and spectral resolution through successive ignition.

In order to solve the problems of the technologies described above, the technical solution used in the present invention is:

Improve a method for AOTF imaging space resolution and spectral resolution, comprise the steps:

A, first AOTF angle of diffraction broadening to be measured, then AOTF diffraction spectrum broadening is measured, draw diffraction efficiency (x through the two measurement _i+m, y _j, λ _k, md λ);

B, obtain measured target at the picture dot (x of CCD by AOTF light spectrum image-forming _i, y _j) the light intensity I that detects ⁰(x _i, y _j, λ _k);

C, carry out successive ignition by formula, described formula is:

$I^n(x_i,y_j,{\mathrm{\λ}}_k)=\frac{I^0(x_i,y_j,{\mathrm{\λ}}_k)-\underset{\begin{array}{c}m=-M\\ m\≠0\end{array}}{\overset{M}{\Σ}}\mathrm{\η}(x_{i+m},y_j,{\mathrm{\λ}}_k,md\mathrm{\λ})I^{n-1}(x_{i+m},y_j,{\mathrm{\λ}}_k+md\mathrm{\λ})}{\mathrm{\η}(x_i,y_j,{\mathrm{\λ}}_k,0)}$

In above formula, I ⁿ(x _i, y _j, λ _k) when being n-th iteration, (x _i, y _j) place's wavelength is λ _ktime light intensity; I ⁰(x _i, y _j, λ _k) light intensity for detecting in above-mentioned b step; η (x _i+m, y _j, λ _k, md λ) for peak wavelength be λ _ktime, target (x _i+m, y _j) after AOTF, wavelength is λ _kthe diffraction efficiency of+md λ, obtains by measuring in above-mentioned a step; I ^n-1(x _i+m, y _j, λ _k+ md λ) when being (n-1)th iteration, (x _i+m, y _j) place's wavelength is λ _klight intensity during+md λ; η (x _i, y _j, λ _k, 0) for peak wavelength be λ _ktime, target (x _i, y _j) after AOTF, wavelength is λ _kdiffraction efficiency;

Iterations stop condition is:

$\frac{\underset{{\mathrm{\λ}}_k={\mathrm{\λ}}_{N1}}{\overset{{\mathrm{\λ}}_{N2}}{\Σ}}\underset{y_j=y_{N1}}{\overset{y_{N2}}{\Σ}}\underset{x_i=x_{N1}}{\overset{x_{N2}}{\Σ}}\left|\frac{I^n(x_i,y_j,{\mathrm{\λ}}_k)-I^{n-1}(x_i,y_j,{\mathrm{\λ}}_k)}{I^n(x_i,y_j,{\mathrm{\λ}}_k)}\right|}{(x_{N2}-x_{N1})(y_{N2}-y_{N1})\[({\mathrm{\λ}}_{N2}-{\mathrm{\λ}}_{N1})/({\mathrm{\λ}}_k-{\mathrm{\λ}}_{k-1})\]}\≤\mathrm{\σ}$

In above formula, σ is the average rate of change of the twice each picture dot detected intensity in front and back in iteration;

(x _n2~ x _n1) (y _n2~ y _n1) (λ _n2~ λ _n1) be data cube block;

Wherein, data cube block (x _n2~ x _n1) (y _n2~ y _n1) (λ _n2~ λ _n1) select the region that has obvious light and shade to change, and (x _n2~ x _n1) (y _n2~ y _n1) (λ _n2~ λ _n1) and σ should select according to measuring accuracy in reality and the requirement of operation time.

Carry out measurement to AOTF angle of diffraction broadening in described a step to be specially: white light source, spectroscope, CCD camera are arranged in order, be arranged in sequence with the frosted glass of slit, parallel light tube, AOTF and telescope in described spectroscope, also index dial is provided with in described spectroscope, white light source is radiated on the frosted glass with slit, from parallel light tube, the light of slit is become directional light, and entering in tested AOTF, the light after AOTF diffraction is imaged in CCD camera by telescope again.

The minimum angles measuring accuracy of described index dial is 1'=(1/60) °, and the resolution of described CCD camera is 640 × 480Pix, and the angle-measurement accuracy of angle measurement system can reach 0.0015 °.

The spectrometer measurement adopting high spectral resolution to the measurement of AOTF diffraction spectrum broadening in described a step.

In described b step, preposition optical system, AOTF, rearmounted optical system and AOTF light spectrum image-forming CCD camera are arranged in order and measure.

The beneficial effect that compared with prior art the present invention has is:

The method, by successive ignition optimization process AOTF imaging spectrometer data cube, improves spatial resolution and the spectral resolution of AOTF imaging;

The angle measurement system that the method adopts spectroscope and CCD to combine measures AOTF angle of diffraction broadening, angle-measurement accuracy can reach 0.0015 °, and adopt the spectrometer of high spectral resolution to record AOTF diffraction spectrum and survey broadening, obtain the corresponding relation of AOTF angle of diffraction broadening and diffraction spectrum broadening;

When the method measures AOTF angle of diffraction broadening and diffraction spectrum broadening, after a corresponding AOTF only needs once complete measurement, only need call, without the need to duplicate measurements in follow-up use;

The method, also without the need to changing hardware device, only need be optimized follow-up data and processing.

Accompanying drawing explanation

Below by accompanying drawing, the specific embodiment of the present invention is described in further detail.

Fig. 1 is process flow diagram of the present invention;

Fig. 2 is AOTF angle of diffraction broadening measurement mechanism structural drawing;

Fig. 3 is AOTF light spectrum image-forming structural drawing in the present invention;

Fig. 4 is CCD picture dot detection actual light intensity schematic diagram;

Fig. 5 is successive ignition AOTF light spectrum image-forming data cube schematic diagram;

Fig. 6 a is horizontal narrow slit CCD image in embodiment;

Fig. 6 b is vertical slit CCD image in embodiment;

Fig. 6 c is horizontal narrow slit and vertical slit image bandwidth comparison diagram in embodiment;

Fig. 7 a is for working as ultrasound drive frequency f _aduring=110MHz, angle of diffraction broadening measurement result figure;

Fig. 7 b is for working as ultrasound drive frequency f _aduring=110MHz, diffraction spectrum broadening measurement result figure;

When Fig. 8 a is n=0, the CCD image of vertical slit;

When Fig. 8 b is n=5, the CCD image of vertical slit;

Fig. 8 c is the CCD image of horizontal narrow slit;

Fig. 8 d is the slit image bandwidth comparison diagram of Fig. 8 a, Fig. 8 b and Fig. 8 c.

In figure: 1 be white light source, 2 be spectroscope, 3 is CCD camera, 4 is be parallel light tube with the frosted glass, 5 of slit, 6 be AOTF, 7 be telescope, 8 be index dial, 9 be preposition optical system, 10 be rearmounted imaging optical system, 11 be AOTF light spectrum image-forming CCD camera.

Embodiment

The invention will be further described by reference to the accompanying drawings for embodiment below.

As shown in Figure 1, under filtering at each central peak wavelength of AOTF, first S101 is measured to AOTF angle of diffraction broadening, and S102 is measured to AOTF diffraction spectrum broadening, obtain the corresponding relation of AOTF angle of diffraction broadening and diffraction spectrum broadening, for follow-up data processing provides necessary parameter; The data obtained by AOTF light spectrum image-forming S103CCD, by computing machine successive ignition optimization process S104, finally realize the object of high AOTF imaging space resolution and spectral resolution.

Because the ultrasonic transducer in AOTF is rectangular configuration, will cause ultrasonicly there is acoustic wave diffraction when entering acousto-optic crsytal like this, and therefore cause ultrasound wave to lose direction and there is certain broadening, and ultrasonic acoustic pressure on different directions is different.According to AOTF momentum matching condition, ultrasound wave loses the broadening in direction will cause the broadening of diffraction spectrum, and the difference of ultrasound wave acoustic pressure is by different for the diffraction efficiency of not sharing the same light after causing diffraction spectrum broadening.

AOTF exit facet in present embodiment has adopted wedge mode to eliminate image drift.

As shown in Figure 2, AOTF angle of diffraction broadening is measured S101 and is comprised white light source 1, spectroscope 2 and CCD camera 3, white light source 1 is radiated at spectroscope 2 front end with on the frosted glass 4 of slit, from parallel light tube 5, the light of slit is become directional light, and entering in tested AOTF6, the light after AOTF6 diffraction is imaged in CCD camera 3 by telescope 7 again.The angle-measurement accuracy that the index dial 8 of spectroscope 2 is minimum is 1'=(1/60) °, and the resolution of CCD camera 3 is 640 × 480Pix, and CCD camera 3 is fixed on the rear end of telescope 7.When rotation telescope 7 makes very big position, the center of slit image move to the rightmost side from the leftmost side of CCD camera 3, the scale that corresponding spectroscope 2 turns over is 58', therefore the angle-measurement accuracy of this angle measurement system can reach 58'/480 ≈ 0.0015 °, the angle of diffraction broadening that what this measurement recorded is outside AOTF6 is not the intracrystalline angle of diffraction broadening of AOTF6.Certainly, if the CCD adopting picture dot size less in CCD camera 3 measures, angle-measurement accuracy can be higher.

AOTF diffraction spectrum broadening is measured S102 and is adopted the spectrometer of high spectral resolution to record.Spectral resolution is adopted to be the fiber spectrometer of 0.25nm@λ=600nm in present embodiment.

It is be that 0.1nm interval arranges AOTF sweep interval with wavelength that AOTF angle of diffraction broadening is measured in S101 and AOTF diffraction spectrum broadening measurement S102, and measure spectrum scope is 450nm-700nm.

The picture of horizontal narrow slit and vertical slit that CCD camera 3 obtains same width is to such as Fig. 6 a and Fig. 6 b, extract the 300th row of Fig. 6 a and the 250th row contrast slit image broadening of Fig. 6 b, horizontal narrow slit and vertical slit image wide-band ratio are more as fig. 6 c, as can be seen from Fig. 6 c, compared with horizontal narrow slit imaging, not only there is secondary lobe in vertical slit image, and the broadband of principal maximum is also wide compared with horizontal narrow slit, namely there is broadening in AOTF diffraction direction, at AOTF ultrasound drive frequency f _aduring=120MHz, the half-peak breadth of vertical slit image principal maximum is 3.5 times of horizontal narrow slit imaging.

AOTF angle of diffraction broadening is measured S101 and AOTF diffraction spectrum broadening and is measured S102 comparing result as shown in figs. 7 a and 7b.As ultrasound drive frequency f _aduring=110MHz, as shown in Figure 7a, diffraction spectrum broadening measurement result as shown in Figure 7b for angle of diffraction broadening measurement result, from Fig. 7 a and Fig. 7 b, angle of diffraction broadening and diffraction spectrum broadening substantially identical, comprise characteristic spectrum and also can coincide very well, as Fig. 7 a and Fig. 7 b elliptic region.

AOTF angle of diffraction broadening is measured S101 and AOTF diffraction spectrum broadening and is measured S102, mainly for obtaining the corresponding relation of the lower AOTF angle of diffraction broadening of each AOTF optical filtering and diffraction spectrum broadening, for follow-up successive ignition provides necessary parameter.Although AOTF angle of diffraction broadening is measured S101 and AOTF diffraction spectrum broadening and measured S102 more complicated, data volume is large, for an AOTF6, only needs once comprehensively to measure, only needs directly to apply these parameters in follow-up light spectrum image-forming.

As shown in Figure 3, AOTF light spectrum image-forming S103 comprises the AOTF light spectrum image-forming CCD camera 11 of preposition optical system 9, AOTF6, rearmounted imaging optical system 10 and imaging.For the ease of comparing, the optical system of the optical system employing AOTF angle of diffraction broadening measurement S101 that AOTF light spectrum image-forming S103 is all is identical, and wavelength interval is 0.1nm, measure spectrum scope is 550nm-700nm, but employing measures the different white light source of S101 from AOTF angle of diffraction broadening.

As shown in Figure 4, the filter wavelength arranged as AOTF6 is λ _ktime, if AOTF6 is desirable light spectrum image-forming, should be that picture dot and the extraterrestrial target of AOTF light spectrum image-forming CCD camera 11 is one-to-one relationships, i.e. picture dot (the x of CCD _i, y _j) detection light intensity be extraterrestrial target (x _i, y _j) place's wavelength is λ _klight intensity; But because AOTF6 angle of diffraction and diffraction light exist broadening, the filter wavelength that therefore AOTF6 is arranged is λ _ktime, the picture dot (x of CCD _i, y _j) the light intensity I that detects ⁰(x _i, y _j, λ _k) be:

$I^0(x_i,y_j,{\mathrm{\λ}}_k)=\mathrm{\η}(x_i,y_j,{\mathrm{\λ}}_k,0)I(x_i,y_j,{\mathrm{\λ}}_k)+\underset{\begin{array}{c}m=-M\\ m\≠0\end{array}}{\overset{M}{\Σ}}\mathrm{\η}(x_{i+m},y_j,{\mathrm{\λ}}_k,md\mathrm{\λ})I(x_{i+m},y_j,{\mathrm{\λ}}_k+md\mathrm{\λ})---\left(1\right)$

Wherein, I (x _i, y _j, λ _k) be target (x _i, y _j) place's wavelength is λ _ktime true light intensity; η (x _i+m, y _j, λ _k, md λ) and be peak wavelength be λ _ktime, target (x _i+m, y _j) after AOTF6, wavelength is λ _kthe diffraction efficiency of+md λ.

Therefore, target (x _i, y _j) the real intensity I (x at place _i, y _j, λ _k) be:

$I(x_i,y_j,{\mathrm{\λ}}_k)=\frac{I^0(x_i,y_j,{\mathrm{\λ}}_k)-\underset{\begin{array}{c}m=-M\\ m\≠0\end{array}}{\overset{M}{\Σ}}\mathrm{\η}(x_{i+m},y_j,{\mathrm{\λ}}_k,md\mathrm{\λ})I(x_{i+m},y_j,{\mathrm{\λ}}_k+md\mathrm{\λ})}{\mathrm{\η}(x_i,y_j,{\mathrm{\λ}}_k,0)}---\left(2\right)$

Wherein, I ⁰(x _i, y _j, λ _k) can be obtained by AOTF light spectrum image-forming CCD camera 11, η (x _i+m, y _j, λ _k, md λ) and measure S101 and AOTF diffraction spectrum broadening measurement S102 acquisition by AOTF angle of diffraction broadening, from (2) formula, real intensity I (x be obtained _i, y _j, λ _k) also need to know I (x _i+m, y _j, λ _k+ md λ), and I (x _i+m, y _j, λ _k+ md λ) need successive ignition to go to approach.

As shown in Figure 5, concrete derivation is as follows:

$I^n(x_i,y_j,{\mathrm{\λ}}_k)=\frac{I^0(x_i,y_j,{\mathrm{\λ}}_k)-\underset{\begin{array}{c}m=-M\\ m\≠0\end{array}}{\overset{M}{\Σ}}\mathrm{\η}(x_{i+m},y_j,{\mathrm{\λ}}_k,md\mathrm{\λ})I^{n-1}(x_{i+m},y_j,{\mathrm{\λ}}_k+md\mathrm{\λ})}{\mathrm{\η}(x_i,y_j,{\mathrm{\λ}}_k,0)}---\left(3\right)$

Wherein, I ⁿ(x _i, y _j, λ _k) when being n-th iteration, (x _i, y _j) place's wavelength is λ _ktime light intensity; I (x _i+m, y _j, λ _k+ md λ) adopt previous I ^n-1(x _i+m, y _j, λ _k+ md λ) replace, go to approach by successive ignition.Spectrum interval (λ wherein in the value of M and d λ and AOTF light spectrum image-forming _k+1-λ _k), angle of diffraction broadening is relevant with the focal distance f of rearmounted imaging optical system 10.Iterations stop condition according to actual requirement choose reasonable, as shown in the formula:

$\frac{\underset{{\mathrm{\λ}}_k={\mathrm{\λ}}_{N1}}{\overset{{\mathrm{\λ}}_{N2}}{\Σ}}\underset{y_j=y_{N1}}{\overset{y_{N2}}{\Σ}}\underset{x_i=x_{N1}}{\overset{x_{N2}}{\Σ}}\left|\frac{I^n(x_i,y_j,{\mathrm{\λ}}_k)-I^{n-1}(x_i,y_j,{\mathrm{\λ}}_k)}{I^n(x_i,y_j,{\mathrm{\λ}}_k)}\right|}{(x_{N2}-x_{N1})(y_{N2}-y_{N1})\[({\mathrm{\λ}}_{N2}-{\mathrm{\λ}}_{N1})/({\mathrm{\λ}}_k-{\mathrm{\λ}}_{k-1})\]}\≤\mathrm{\σ}---\left(4\right)$

Wherein represent the average rate of change of twice each picture dot detected intensity before and after in iteration on the right of (4) formula equal sign, its value can be more and more less along with the increase of iterations, and therefore σ selects less, and result of calculation is more accurate, but computing is also larger; Wherein (x _n2~ x _n1) * (y _n2~ y _n1) * (λ _n2~ λ _n1) for selecting the data cube block of iterations stop condition, it is more large more accurate, but operand is larger; At selection (x _n2~ x _n1) * (y _n2~ y _n1) time should select the region of significant change.Therefore, (x _n2~ x _n1) * (y _n2~ y _n1) * (λ _n2~ λ _n1) and σ should according to actual requirement choose reasonable.In present embodiment, iteration stopping condition is elected as: x _n1=250, x _n2=390, y _n1=220, x _n2=260, λ _n1=550nm, λ _n2=620nm, σ=0.00001.As shown in Figure 8, as seen from Figure 8, vertically slit image is substantially identical with the bandwidth of horizontal narrow slit picture later for successive ignition, and this will improve AOTF imaging space resolution in final experimental result contrast.According to (3) formula, because this successive ignition optimized algorithm has deducted the impact of diffraction spectrum broadening, therefore the spectral resolution of AOTF have also been obtained raising.

Claims (5)

1. improve a method for AOTF imaging space resolution and spectral resolution, it is characterized in that, comprise the steps:

A, first AOTF angle of diffraction broadening to be measured, then AOTF diffraction spectrum broadening is measured, draw diffraction efficiency (x through the two measurement _i+m, y _j, λ _k, md λ);

B, obtain measured target at the picture dot (x of CCD by AOTF light spectrum image-forming _i, y _j) the light intensity I that detects ⁰(x _i, y _j, λ _k);

C, carry out successive ignition by formula, described formula is:

$I^n(x_i,y_j,{\mathrm{\λ}}_k)=\frac{I^0(x_i,y_j,{\mathrm{\λ}}_k)-\underset{\begin{array}{c}m=-M\\ m\≠0\end{array}}{\overset{M}{\Σ}}\mathrm{\η}(x_{i+m},y_j,{\mathrm{\λ}}_k,md\mathrm{\λ})I^{n-1}(x_{i+m},y_j,{\mathrm{\λ}}_k,md\mathrm{\λ})}{\mathrm{\η}(x_i,y_j,{\mathrm{\λ}}_k,0)}$

In above formula, I ⁿ(x _i, y _j, λ _k) when being n-th iteration, (x _i, y _j) place's wavelength is λ _ktime light intensity; I ⁰(x _i, y _j, λ _k) light intensity for detecting in above-mentioned b step; η (x _i+m, y _j, λ _k, md λ) for peak wavelength be λ _ktime, target (x _i+m, y _j) after AOTF, wavelength is λ _kthe diffraction efficiency of+md λ, obtains by measuring in above-mentioned a step; I ^n-1(x _i+m, y _j, λ _k+ md λ) when being (n-1)th iteration, (x _i+m, y _j) place's wavelength is λ _klight intensity during+md λ; η (x _i, y _j, λ _k, 0) for peak wavelength be λ _ktime, target (x _i, y _j) after AOTF, wavelength is λ _kdiffraction efficiency;

Iterations stop condition is:

$\frac{\underset{{\mathrm{\λ}}_k={\mathrm{\λ}}_{N1}}{\overset{{\mathrm{\λ}}_{N2}}{\Σ}}\underset{y_j=y_{N1}}{\overset{y_{N2}}{\Σ}}\underset{x_i=x_{N1}}{\overset{x_{N2}}{\Σ}}\left|\frac{I^n(x_i,y_j,{\mathrm{\λ}}_k)-I^{n-1}(x_i,y_j,{\mathrm{\λ}}_k)}{I^n(x_i,y_j,{\mathrm{\λ}}_k)}\right|}{(x_{N2}-x_{N1})(y_{N2}-y_{N1})\[({\mathrm{\λ}}_{N2}-{\mathrm{\λ}}_{N1})/({\mathrm{\λ}}_k-{\mathrm{\λ}}_{k-1})\]}\≤\mathrm{\σ}$

In above formula, σ is the average rate of change of the twice each picture dot detected intensity in front and back in iteration;

(x _n2~ x _n1) (y _n2~ y _n1) (λ _n2~ λ _n1) be data cube block;

Wherein, data cube block (x _n2~ x _n1) (y _n2~ y _n1) (λ _n2~ λ _n1) select the region that has obvious light and shade to change, and (x _n2~ x _n1) (y _n2~ y _n1) (λ _n2~ λ _n1) and σ should select according to measuring accuracy in reality and the requirement of operation time.

2. a kind of method improving AOTF imaging space resolution and spectral resolution according to claim 1, it is characterized in that, carry out measurement to AOTF angle of diffraction broadening in described a step to be specially: by white light source (1), spectroscope (2), CCD camera (3) is arranged in order, the frosted glass (4) with slit is arranged in sequence with in described spectroscope (2), parallel light tube (5), AOTF (6) and telescope (7), index dial (8) is also provided with in described spectroscope (2), white light source (1) is radiated on the frosted glass (4) with slit, from parallel light tube (5), the light of slit is become directional light, and enter in tested AOTF (6), light after AOTF (6) diffraction is imaged in CCD camera (3) by telescope (7) again.

3. a kind of method improving AOTF imaging space resolution and spectral resolution according to claim 2, it is characterized in that: the minimum angles measuring accuracy of described index dial (8) is 1'=(1/60) °, the resolution of described CCD camera (3) is 640 × 480Pix, and the angle-measurement accuracy of angle measurement system can reach 0.0015 °.

4. a kind of method improving AOTF imaging space resolution and spectral resolution according to claim 1, is characterized in that, is the spectrometer measurement adopting high spectral resolution in described a step to the measurement of AOTF diffraction spectrum broadening.

5. a kind of method improving AOTF imaging space resolution and spectral resolution according to claim 1, it is characterized in that, in described b step, preposition optical system (9), AOTF (6), rearmounted optical system (10) and AOTF light spectrum image-forming CCD camera (11) are arranged in order and measure.