The static Fourier transform interference imaging spectrum full-polarization sniffer
Technical field
The present invention relates to the optical instrument technical field, particularly a kind of while can obtain the Trinitarian static Fourier transform interference imaging spectrum full-polarization sniffer of target two dimension intensity, interference spectrum and full polarization characteristic.
Background technology
1980s, US Air aerodynamic force laboratory (JPL) proposes the imaging spectrometer notion, and imager and spectrometer are merged, and can obtain the two-dimensional space information and the one dimension spectral information of target simultaneously, is subjected to various countries and payes attention to energetically.In more than 20 year time, imaging spectrometer is from multichannel color dispersion-type, develop into the interfere type of high spectrum, wherein Michelson (Mechelson) inteference imaging spectrometer has the bigger principal advantages in visual field, the interfere type beam-splitting structure has guaranteed the spectrally resolved ability that it is high, big visual field has also guaranteed the signal to noise ratio (S/N ratio) that it is higher, and these advantages are adopted it in a large number in earth observation.But when index glass scan mode commonly used is surveyed, same target interference strength need index glass repeatedly stepping gather, what obtain is different values constantly, the measuring error that causes is bigger; The driving of inner scanning mirror needs very high precision, and vibrations sensitivity to external world.These problems are used it in space flight, aviation, field environment have big limitation.Development has afterwards played static Fourier and has changed spectrometer, one of typical case's representative is exactly the static interferometer of Michelson (Mechelson) type, it utilizes one of them mirror tilt to produce optical path difference, on interference surface, produce vertical interference fringe, utilize Fourier transform to obtain the spectrum of light source again.This structure does not have complicated mechanical scanning, and is simple in structure, with low cost, is convenient to miniaturization and debugging conveniently, and the earth observation spectral measurement is significant for advancing.
Yet we notice: the illumination of light emitted is mapped to any target in earth surface and the atmosphere, in the process of radiation, reflection, transmission and diffuse lightwave, not only can cause the variation of light wave intensity, spectral characteristics of radiation, also can cause the variation of polarization state.Inteference imaging spectrometer has solved the function of while detection of a target spatial-intensity information and spectral information goodly, can obtain two-dimensional space information and the structure of matter and the chemical constitution of target, yet can't embody the polarization characteristic that characterizes thingness comprehensively.
Summary of the invention
Can not obtain the problem of the full polarization characteristic of target at present Michelson (Mechelson) type static Fourier transform hyperspectral imager, the object of the present invention is to provide a kind of simple and compact for structure, movement-less part, luminous flux big, can disposable acquisition target two-dimensional space picture, the static Fourier transform interference imaging spectrum full-polarization sniffer of one dimension spectral information and complete polarization information.
In order to reach the foregoing invention purpose, the present invention adopts and is achieved with lower device.
The static Fourier transform interference imaging spectrum full-polarization sniffer, comprise the preposition optical telescope 1, static all-optical modulation module 2, static Fourier transform interference imaging spectrum instrument 3, imaging mirror group 4, the planar array detector 5 that are provided with along the optical transmission direction order, planar array detector 5 obtains with disposal system 6 with signal and is connected.
Described preposition optical telescope 1 comprises the preposition optical system lens group 11 that is provided with in order, and diaphragm 12 and preposition optical system are as Fang Jing group 13; Preposition optical system lens group 11 can be reflector group, catadioptric mirror group or refracting set.
Described diaphragm 12 is an aperture diaphragm 121 under space-time hybrid modulation situation, is a slit 122 under the spatial modulation situation.
Described static all-optical modulation module 2 is made up of birefringece crystal group 21 and subsequent polaroid or polarizing prism 22.
Described static Fourier transform interference imaging spectrum instrument 3 comprises that normal has the horizontal glass 33 of angle perpendicular to horizontal glass 31, spectroscope 32, normal and the incident light axis of primary optical axis.
Described imaging mirror group 4 selects for use following arbitrary scheme to make:
Under the spatial modulation situation, be a cylindrical lens 41 and subsequent imaging len 42, the focal plane of cylindrical lens 41 is positioned on the follow-up imaging len 42, and the focal plane of imaging len 42 is positioned on the follow-up planar array detector 5;
Under the space-time hybrid modulation situation, be imaging len 42, its focal plane is positioned on the follow-up planar array detector 5.
Described planar array detector 5 is made of ccd array, CMOS array, photodiode array, photomultiplier tube array, infrared focal plane array or ultraviolet light detector array.
Described signal obtains the microcomputer that carries out Fourier transform processing by the information that planar array detector 5 can be received with disposal system 6 and constitutes, and is used to demodulate two-dimensional space intensity, one dimension spectrum and four Stokes vectors of target, and is shown as the pseudo-colours picture.
The static all-optical modulation module that the present invention adopts birefringece crystal to constitute carries out phase modulation (PM) respectively to four Stokes vectors: adopt preposition optical telescope that the light from the incident of object target is become directional light and incide the static all-optical modulation module, make four Stokes vectors of incident light obtain different modulating respectively, thereby on phase place, separate, to realize the extraction of full polarization characteristic; Adopt Michelson (Mechelson) type static Fourier transform interference instrument as beam split, interfere core component: incident light is by behind the spectroscope, form two row light waves: row are reflected, behind the original position of vertical horizontal glass 31 reflected back light splitting surfaces 32, see through the spectroscope outgoing again; Another row are by light splitting surface 32 transmissions, pass through low-angle horizontal glass 33 reflected back light splitting surfaces 32 again after, produce a transversal displacement with original position, and further reflected by light splitting surface.So this two row homology light wave wavefront spatially is separated through behind the different approach, becomes coherent light, they by imaging mirror group after, interfere, on the planar array detector that is positioned on the imaging mirror focal plane, form interference pattern, realize spectrum beam split function, reach the high spectral resolution ability.
Interference imaging spectral polarization detecting device of the present invention is compared with other existing apparatus, it is advantageous that:
A) the present invention has realized that full polarization information, high-resolution imaging, the high spectral information trinity obtains;
B) whole device is big visual field, high s/n ratio, static structure: the core light spectrometer is that Michelson (Mechelson) type static Fourier changes spectrometer architecture, visual field and corresponding high s/n ratio that it is bigger have been guaranteed, and without any the parts of motion, the antivibration ability is strong;
C) except that planar array detector and signal obtain with disposal system, whole device is a full light structural: no any electric light, acousto-optic or magneto-optic modulation mechanism in the process that polarization information and spectral information obtain, can realize the complete real-time detection of polarization information.The automatically controlled non real-time that causes has been avoided in the electrical noise influence that passive structures has avoided electrical modulation to bring on the one hand on the other hand, has also reduced the difficulty of signal controlling and demodulation process simultaneously;
D) whole device luminous flux is big, highly sensitive, resolution is high, spectral range is wide, the later stage signal Processing is simple, and design, processing, cost are low, help promotion and application.
Description of drawings
Fig. 1 is a structural representation of the present invention.
Fig. 2 is the structural representation of diaphragm 12 of the present invention, and wherein, Fig. 2 (a) is under space-time hybrid modulation situation, and diaphragm 12 is the structural representation of an aperture diaphragm 121; Fig. 2 (b) is under the spatial modulation situation, and diaphragm 12 is the structural representation of a slit 122.
Fig. 3 is the structural representation of imaging mirror group 4 of the present invention, and wherein, Fig. 3 (a) is under space-time hybrid modulation situation, and imaging mirror group 4 is the structural representation of imaging len 42; Fig. 3 (b) is under the spatial modulation situation, the structural representation of imaging mirror group 4 for being made of a cylindrical lens 41 and subsequent imaging len 42.
Embodiment
Below in conjunction with the drawings and specific embodiments the present invention is described in further details.
With reference to Fig. 1, the static Fourier transform interference imaging spectrum full-polarization sniffer, comprise the preposition optical telescope 1, static all-optical modulation module 2, static Fourier transform interference imaging spectrum instrument 3, imaging mirror group 4, the planar array detector 5 that are provided with along the optical transmission direction order, signal obtains and disposal system 6.
Described preposition optical telescope 1 is positioned at whole device foremost, comprises the preposition optical system lens group 11 that is provided with in order, and diaphragm 12 and preposition optical system are as Fang Jing group 13; Preposition optical system lens group 11 can be reflector group, catadioptric mirror group or refracting set; Preposition optical telescope 1 is used for gathering and the collimation target light, eliminates parasitic light simultaneously.
With reference to Fig. 2, described diaphragm 12 is an aperture diaphragm 121 under space-time hybrid modulation situation, is a slit 122 under the spatial modulation situation.
Described static all-optical modulation module 2 is positioned at the back of preposition optical telescope 1, is made up of birefringece crystal group 21 and subsequent polaroid or polarization crystal 22; Static all-optical modulation module 2 is used for four Stokes vector spectral modulation of target light that will collimation to the carrier wave of different frequency, makes four Stokes vector S
0, S
1, S
2, S
3Has different phase places respectively.
Described static Fourier transform interference imaging spectrum instrument 3 comprises that normal has the horizontal glass 33 of angle perpendicular to horizontal glass 31, spectroscope 32, normal and the incident light axis of primary optical axis; Static Fourier transform interference imaging spectrum instrument 3 is positioned at the back of static all-optical modulation module 2, is used for the transmission light of aforementioned different wave length is divided into two bundle coherent lights, realizes spectrum beam split function, reaches the high spectral resolution ability.
With reference to Fig. 3, described imaging mirror group 4 selects for use following arbitrary scheme to make:
Under the spatial modulation situation, be a cylindrical lens 41 and subsequent imaging len 42, the focal plane of cylindrical lens 41 is positioned on the follow-up imaging len 42, and the focal plane of imaging len 42 is positioned on the follow-up planar array detector 5;
Under the space-time hybrid modulation situation, be imaging len 42, its focal plane is positioned on the follow-up planar array detector 5.
Imaging mirror group 4 is used for the light of static Fourier transform interference imaging spectrum instrument 3 outgoing is focused on planar array detector 5.
Described planar array detector 5 is a photoelectric commutator, is positioned on the focal plane of imaging mirror 4, is made of ccd array, CMOS array, photodiode array, photomultiplier tube array, infrared focal plane array or ultraviolet light detector array.Planar array detector 5 is used to receive the emergent light of imaging mirror, obtains image, spectrum and whole polarization information of target light, and the electric signal of its output is sent into follow-up signal and obtained and disposal system 6.
Described signal obtains the microcomputer that carries out Fourier transform processing by the information that planar array detector 5 can be received with disposal system 6 and constitutes, and is used to demodulate two-dimensional space intensity, one dimension spectrum and four Stokes vectors of target, and is shown as the pseudo-colours picture.
Principle of work of the present invention is: the light that target source sends collimates by preposition optical system 1 after 2 modulation of static all-optical modulation module, behind transmission light process Michelson (Mechelson) the type static Fourier transform interference imaging spectrum instrument 3 after the modulation, emergent light becomes two bundle coherent lights, this two-beam converges on the planar array detector 5 imaging and interferes after imaging mirror group 4, the signal that planar array detector 5 receives obtains image, spectrum and the polarization information that can obtain target after handling with disposal system 6 through signal again.
In the accompanying drawing: the preposition optics of 1-is looked far into the distance system; The preposition optical system lens group of 11-wherein; The 12-diaphragm, 121-aperture diaphragm wherein, the form that in space-time hybrid modulation system, adopts for diaphragm 12; The 122-slit, the form that in the spatial modulation system, adopts for diaphragm 12; The preposition optical system of 13-picture side set of lenses; 2-static all-optical Polarization Modulation module; 21-birefringence crystal group; 22-polarizer or polarization prism; 3-static Fourier transform interference imaging spectrum instrument; The 31-normal has the horizontal glass M2 of little angle perpendicular to horizontal glass M1,32-spectroscope PS, 33-normal and the incident light axis of key light axle; 4-imaging lens group, wherein 41-cylinder lens; The 42-imaging len, 41 are connected successively with 42, consist of the set of lenses 4 that adopts in the spatial modulation system; The 42-imaging len consists of separately the set of lenses 4 that adopts in the space-time hybrid modulation system; The 5-planar array detector; 6-signal acquisition and treatment system.