CN104729691B - Terahertz detector parameter measuring apparatus and measuring method - Google Patents

Abstract

The present invention proposes a kind of terahertz detector parameter measuring apparatus and measuring method, for measuring the parameters such as the responsiveness of various terahertz detector.The present invention uses standard terahertz detector and the method for terahertz detector matching measurement to be measured with absolute response degree: with reference to the terahertz emission in terahertz emission source, background radiation with liquid nitrogen refrigerating black matrix, it is modulated into periodically variable terahertz emission signal by chopper blade, optical system is alternately incided within a cycle, it is ultimately incident upon on standard terahertz detector or terahertz detector to be measured, be converted to periodically variable voltage signal, then obtain measurement voltage signal through lock-in amplifier process；It is calculated the parameters such as the responsiveness of terahertz detector to be measured, noise equivalent power according to by the absolute response angle value of standard terahertz detector.Apparatus of the present invention are placed in the cryogenic vacuum background channel of liquid nitrogen refrigerating, greatly reduce the impact that terahertz detector parameter is accurately measured by background noise.

Description

Terahertz detector parameter measuring apparatus and measuring method

Technical field

The invention belongs to technical field of optical measurement, relate generally to a kind of terahertz measuring apparatus and measuring method, especially Relate to a kind of terahertz detector parameter measuring apparatus and measuring method.

Background technology

In recent years, Terahertz Technology is the intercrossing forward position new and high technology of domestic and international primary study, safety check, anti-terrorism, There is huge application prospect in the fields such as survey of deep space, end communication, medical science, material detection.Wherein terahertz detector Development, to produce be the crucial problem of the restriction area researches such as terahertz imaging detection, communication.

Terahertz detector mainly includes that Golay detector, Bolometer detector, Thomas detector, heat are released Electricity terahertz detector, Schottky diode, terahertz pulse photoconduction exploring antenna, Terahertz heterodyne detector etc., These several terahertz detector wavelength band cover whole terahertz wave band (0.1～10) THz, i.e. (30～3000) μm, and responsiveness has the biggest difference.Therefore, in development, production and the application process of various terahertz detectors, In the urgent need to the terahertz detector power parameter of different responsivenesses is measured respectively, grind for Terahertz application system Offer value guarantee is provided.

At present, disclosed terahertz detector measurement method of parameters only has German National quantitative study institute (PTB) to carry out Research, its method is to use black matrix as terahertz emission source, and the chopped device of radiation that black matrix sends is modulated into the cycle Property change square wave, incide on terahertz detector through tera-hertz spectra optical filter, meter calculate Terahertz heat Release the responsivity value of electric explorer.This responsivity value is by the radiance of black matrix, radiating aperture area, black matrix and detection Distance, the output voltage values of Terahertz pyroelectric detector between device are calculated.Owing to this method is by surveying Amount relevant parameter, combined mathematical module is calculated responsivity value, and the error of mathematical model self can cause obtaining Responsivity value is the most accurate.Additionally the experimental provision in the method is to test under normal temperature environment, can exist the biggest Background infrared radiation, thus measurement result is also had the biggest interference.

Summary of the invention

For solving the problem that prior art exists, the present invention proposes a kind of terahertz detector parameter measuring apparatus and survey Metering method, standard terahertz detector and the terahertz detector matching measurement method to be measured with absolute response degree realize Multiple too to pyroelectricity terahertz detector, Golay detector, Bolometer detector, Thomas detector etc. The measurement of hertz detector, and vacuum and low temperature background channel shielding stray radiation is used when measuring, use optical system Assembling terahertz emission, the device compared to Germany PTB is measured in normal temperature environment and is improve measurement signal to noise ratio with accurate Degree.

The technical scheme is that

Described a kind of terahertz detector parameter measuring apparatus, it is characterised in that: include light-source system, optical system, Detection system and data processing module；Described light-source system includes with reference to THz source, low-temp radiating black matrix；Optical system System includes that terahertz emission is modulated into the chopper blade of cyclically-varying square wave, is directional light by terahertz emission collimation Off axis paraboloidal mirror, iris, vacuum and low temperature background channel；Detection system includes standard terahertz detector, treats Survey terahertz detector and lock-in amplifier；

Except the miscellaneous part of vacuum and low temperature background channel is all at vacuum and low temperature background channel in light-source system, optical system In；The luminous position of reference THz source and low-temp radiating black matrix is all in the focus of off axis paraboloidal mirror；Chopper blade Being positioned in the light path of light-source system and off axis paraboloidal mirror, chopper blade rotates according to setpoint frequency, alternately will be with reference to terahertz Hereby the radiation signal in source introduces light path with the radiation reference signal of low-temp radiating black matrix；The outgoing of off axis paraboloidal mirror is parallel Light injects iris, and iris realizes injecting standard terahertz detector and the light beam hole of terahertz detector to be measured Footpath is identical；The output signal of standard terahertz detector and terahertz detector to be measured inputs to number through lock-in amplifier According to processing module.

Further preferred version, described a kind of terahertz detector parameter measuring apparatus, it is characterised in that: optical system System also includes movably for assembling the Terahertz lens of terahertz emission, inside terahertz detector to be measured In time without light cone, Terahertz lens move in the light path between off axis paraboloidal mirror and iris.

Further preferred version, described a kind of terahertz detector parameter measuring apparatus, it is characterised in that: with reference to too Hertz source is divided into for providing the Terahertz alternating temperature black matrix of weak terahertz emission and for providing the terahertz of strong terahertz radiation Hereby Schottky amplifies frequency multiplication source；Standard terahertz detector is divided into low temperature radiometer and Thomas thermal detector；DANGSHEN When examining THz source employing Terahertz alternating temperature black matrix, standard terahertz detector uses low temperature radiometer, with reference to Terahertz When source uses Terahertz Schottky to amplify frequency multiplication source, standard terahertz detector uses Thomas thermal detector；Optics System includes moveable plane mirror, and plane mirror controls Terahertz alternating temperature black matrix or Terahertz as required Schottky amplifies frequency multiplication source and enters light path.

Further preferred version, described a kind of terahertz detector parameter measuring apparatus, it is characterised in that: when to be measured When the responding power upper limit of terahertz detector is less than 10 μ W, use Terahertz alternating temperature black matrix with reference to THz source, when When the responding power upper limit of terahertz detector to be measured is not less than 10 μ W, use Terahertz Schottky with reference to THz source Amplify frequency multiplication source.

Further preferred version, described a kind of terahertz detector parameter measuring apparatus, it is characterised in that: optical system Also including optical filter runner in system, optical filter runner, with reference in the light path between THz source and chopper blade, filters Sheet runner includes the optical filter of multiple corresponding different Terahertz narrow band light spectral coverages.

Further preferred version, described a kind of terahertz detector parameter measuring apparatus, it is characterised in that: low temperature spoke Penetrating black matrix and use liquid nitrogen refrigerating black matrix, vacuum and low temperature background channel housing is divided into two-layer, by note between housing ectonexine Entering liquid nitrogen refrigerating, vacuum and low temperature background channel vacuum is at least up to 10^-4mbar。

A kind of described method utilizing said apparatus to carry out terahertz detector parameter measurement, it is characterised in that: use with Lower step:

Step 1: close with reference to THz source, chopper blade with frequency f by the background radiation of vacuum and low temperature background channel and The radiation of low-temp radiating black matrix is alternatively introduced into light path, standard terahertz detector receive, and obtained by lock-in amplifier Background radiation voltage signal V_0,j, j=1,2 ..., M, M are pendulous frequency；

Step 2: opening with reference to THz source, chopper blade will be black with reference to THz source radiation and low-temp radiating with frequency f The radiation of body is alternatively introduced into light path, standard terahertz detector receive, and obtained voltage signal by lock-in amplifier V_01,j；

Step 3: standard terahertz detector is removed light path, moves into light path by terahertz detector to be measured；Chopper blade With frequency f by being alternatively introduced into light path with reference to the radiation of THz source radiation and low-temp radiating black matrix, Terahertz to be measured visit Survey device receives, and is obtained voltage signal V by lock-in amplifier_sUT,j；

Step 4: obtain terahertz detector to be measured at the terahertz that frequency f, spectrum half-band width are Δ λ by below equation Hereby responsiveness R under the conditions of actinometry_UT(Δ λ, f):

$R_{\mathrm{UT}}(\mathrm{\Δ\λ},f)=\frac{\underset{j=1}{\overset{M}{\mathrm{\Σ}}}(V_{\mathrm{sUT},j}-V_{0,j})}{M*P_{\mathrm{BB}}(\mathrm{\Δ\λ},f)},P_{\mathrm{BB}}(\mathrm{\Δ\λ},f)=\frac{M*R_{01}(\mathrm{\Δ\λ},f)}{\underset{j=1}{\overset{M}{\mathrm{\Σ}}}(V_{01,j}-V_{0,j})}$

Wherein R₀₁(Δ λ is f) standard terahertz detector at the terahertz emission measuring condition that frequency f, spectrum half-band width are Δ λ Under responsivity value；Obtain noise equivalent power NEP of terahertz detector to be measured by below equation, normalization is visited Survey rate D^*:

$\mathrm{NEP}=\frac{\underset{j=1}{\overset{M}{\mathrm{\Σ}}}{V}_{0,j}}{M*R_{\mathrm{UT}}(\mathrm{\Δ\λ},f)},D^{*}=\frac{\sqrt{A\·\mathrm{\Δf}}}{\mathrm{NEP}}$

Wherein A is the area of terahertz detector receiving plane to be measured, and Δ f is measuring circuit bandwidth.

Further preferred version, described a kind of terahertz detector measurement method of parameters, it is characterised in that: when to be measured When terahertz detector is the responding power upper limit weak terahertz detector less than 10 μ W, use too with reference to THz source Hertz alternating temperature black matrix, standard terahertz detector uses low temperature radiometer；When terahertz detector to be measured is responding power When the upper limit is not less than the strong terahertz detector of 10 μ W, Terahertz Schottky is used to amplify frequency multiplication source with reference to THz source, Standard terahertz detector uses Thomas thermal detector.

Beneficial effect

Beneficial effects of the present invention is embodied in the following aspects:

1) apparatus of the present invention use and have the standard terahertz detector of absolute response degree and terahertz detector comparison to be measured Measuring method, by the absolute response angle value measurement of standard terahertz detector obtain terahertz detector to be measured responsiveness, The parameters such as noise equivalent power.During apparatus of the present invention are placed on vacuum and low temperature background channel simultaneously, greatly reduce background The impact of veiling glare.This improves the accuracy of measurement of terahertz detector.

2) present invention uses weak THz source-Terahertz alternating temperature black matrix, strong terahertz source-Terahertz Schottky to amplify frequency multiplication Source, vacuum and low temperature background channel, chopper blade, narrow-band spectrum optical filter and optical system, low temperature radiometer, Tomas Thermal detector constitutes terahertz detector parameter measuring apparatus, and the measurement solving various terahertz detector parameter is difficult Topic.

3) present invention is in the measurements by selecting the narrow-band spectrum optical filter of different terahertz wave band, it is achieved that Terahertz is visited Survey device to measure in the responsiveness of different terahertz wave bands；More weak Terahertz alternating temperature black matrix or stronger Schottky is used to put Big frequency multiplication THz source, it is achieved that the parameter measurement of the terahertz detector of Larger Dynamic scope.Apparatus of the present invention have extensively Wealthy application prospect.

Accompanying drawing explanation

Fig. 1 is that terahertz detector parameter measuring apparatus of the present invention forms schematic diagram.

Fig. 2 is narrow band terahertz band spectral filter runner schematic diagram.

Fig. 3 is chopper blade Principle of Rotating schematic diagram in the present invention.

Detailed description of the invention

With preferred embodiment, the present invention is further described below in conjunction with the accompanying drawings.

The terahertz detector parameter measuring apparatus of the preferred embodiment of the present invention includes light-source system 1, optical system 2, visits Examining system 3 and the computer 4 equipped with terahertz detector parameter measurement data processing software package.

Light-source system includes with reference to THz source, low-temp radiating black matrix.Further it is divided into for carrying with reference to THz source For the Terahertz alternating temperature black matrix 1-1 of weak terahertz emission with for providing the Terahertz Schottky of strong terahertz radiation to amplify Frequency multiplication source 1-2, low-temp radiating black matrix uses the liquid nitrogen refrigerating black matrix 1-3 of the low temperature background radiation providing temperature to be 77K. Terahertz alternating temperature black matrix 1-1 as the weak radiation source of Terahertz, selects the temperature model that Russia Quan E physical study institute develops Enclosing the black matrix for (103K～353K), the emissivity at (30～3000) μm terahertz wave band is 0.97, and it is main Act on is for providing weak terahertz emission signal when measuring.Terahertz Schottky amplifies frequency multiplication source 1-2 as too Hertz substantial radiation source, the model selecting RPG company of Germany to produce is that TX-336 Schottky amplifies frequency multiplication source, and it radiates Frequency is 882.4 μm (0.34THz), and radiant power is 5mW, and its Main Function is to provide strong terahertz radiation when measuring Signal.Liquid nitrogen refrigerating black matrix 1-3 is developed by Quan E physical study institute of Russia, by irrigating liquid nitrogen in black matrix, makes This black matrix operating temperature is 77K, and its Main Function is to provide the lowest a kind of background spoke when terahertz emission is measured Penetrate, this radiation signal and THz source radiation signal alternately enter detector by chopper blade 2-4, it is to avoid the external world The stray radiation interference to measuring signal.

Optical system includes terahertz emission being modulated into the chopper blade 2-4 of cyclically-varying square wave, by terahertz emission Collimation is the off axis paraboloidal mirror 2-6 of directional light, iris 2-9, vacuum and low temperature background channel 2-10, Terahertz are saturating Penetrate window 2-13.Further, optical system also includes movably for assembling the Terahertz of terahertz emission Lens 2-7, when terahertz detector to be measured inside is without light cone, Terahertz lens move into off axis paraboloidal mirror with variable In light path between diaphragm；And moveable plane mirror 2-2, plane mirror controls Terahertz as required Alternating temperature black matrix or Terahertz Schottky amplify frequency multiplication source and enter light path.Optical filter runner 2-1 is also optics in the present embodiment A part for system, in optical filter runner light path between reference THz source and chopper blade, optical filter runner bag Include the optical filter of multiple corresponding different Terahertz narrow band light spectral coverages.

Except the miscellaneous part of vacuum and low temperature background channel is all at vacuum and low temperature background channel in light-source system, optical system In.Vacuum and low temperature background channel 2-10, is divided into two-layer, outer layer to have 6 liquid nitrogen hand-hole 2-11, and internal layer is a diameter of The cavity of 200mm.When liquid nitrogen is injected in the cavity between this passage ectonexine, the temperature of its internal cavity keeps At 77K, effectively shield external stray light, improve accuracy of measurement.Molecular pump group 2-12 uses Britain Edwards The product of the TP-75D model that company produces, for vacuum background channel evacuation, makes vacuum reach 10^-4mbar Magnitude.

Terahertz alternating temperature black matrix 1-1, liquid nitrogen refrigerating black matrix 1-3 are positioned at the left side beam landing position of apparatus of the present invention, and two Person and Terahertz Schottky amplify the luminous position of frequency multiplication source 1-2 all in the focus of off axis paraboloidal mirror 2-6.

Narrow band terahertz band spectral filter runner 2-1 is as in figure 2 it is shown, include 8 holes, and wherein 7 holes are equipped with terahertz Hereby narrow band pass filter, each hole equipped with a kind of optical filter, numbered 1～No. 7.Optical filter uses Russia Tydex 7 kinds of optical filters that company produces.Every kind of optical filter is only through the narrowest tera-hertz spectra, and clear aperature is Φ 24mm, Through the transmitance at peak value and peak value be respectively 30 μm (90%), 105.1 μm (74.9%), 204 μm (75.7%), 301.3 μm (85.9%), 585 μm (89.2%), 980 μm (93.5%), 2970 μm (92.9%), spectrum half-band width Δ λ divides It is not 2.3 μm, 9.4 μm, 28 μm, 45 μm, 66 μm, 203 μm, 458 μm.Filtering as requested during measurement A kind of Terahertz narrow band pass filter or through hole is selected to move into light path on sheet runner 2-1.

Plane mirror 2-2 is the plane mirror that surface is coated with gold film, and this reflecting mirror is placed on the automatically controlled translation of reflecting mirror On platform 2-3.This electronic control translation stage 2-3 use Beijing stand upright Han Guang company produce model be the translation stage of TSA100, its Effect be according to measurement requirement by plane mirror 2-2 into and out light path.

Chopper blade 2-4 is as it is shown on figure 3, use metallic aluminium to make, and its surface is coated with gold film, and its effect is in copped wave control Device 2-5 processed controls lower rotation, alternately will draw with the radiation reference signal of liquid nitrogen black matrix with reference to the radiation signal of THz source Enter optical system.Within a cycle, when chopper blade 2-4 proceeds to light path, can reflect what liquid nitrogen refrigerating black matrix 1-3 sent Radiation, now this chopper blade blocks Terahertz alternating temperature black matrix 1-1 or Terahertz Schottky amplifies what frequency multiplication source 1-2 sent Terahertz emission；When it produces light path, Terahertz alternating temperature black matrix 1-1 or Terahertz Schottky amplification frequency multiplication source 1-2 sends out The terahertz emission that goes out is unobstructed to be received by optical system.Chopper controller 2-5 uses Stamford company of the U.S. to produce The product of SR510 model, can make chopper blade rotate with specific frequency.

Off axis paraboloidal mirror 2-6 uses metallic aluminium to make, and its surface is coated with gold film, and focal length is 900mm, clear aperature For Φ 45mm, its effect be the quasi-value of the light beam that THz source is sent be directional light.

Terahertz lens 2-7 uses Tsurupica or TPX material to make, and clear aperature is Φ 45mm, and focal length is 100mm, its effect is that the directional light received is converged to without on the terahertz detector to be measured of light cone.Automatically controlled flat Moving stage 2-8 use Beijing stand upright Han Guang company produce model be the translation stage of TSA100, its effect be according to measure want Ask Terahertz lens 2-7 into and out light path.

The clear aperature scope of iris 2-9 is (Φ 2～Φ 45) mm, aperture is adjustable guarantee standard terahertz detection It is identical that device receives beam diameter with terahertz detector to be measured.Terahertz transmission window 2-13 uses high density polyethylene (HDPE) Material makes, and has the highest transmitance at terahertz wave band, has the lowest transmitance at infrared band, its effect It is through THz wave, shields infrared stray radiation and incide in apparatus of the present invention in vacuum and low temperature background channel.

Detection system includes standard terahertz detector, terahertz detector to be measured and lock-in amplifier 3-9.Standard is too The output signal of hertz detector and terahertz detector to be measured inputs to data processing module through lock-in amplifier.

The present embodiment Plays terahertz detector is divided into low temperature radiometer 3-1 and Thomas thermal detector 3-2.DANGSHEN When examining THz source employing Terahertz alternating temperature black matrix, standard terahertz detector uses low temperature radiometer, with reference to Terahertz When source uses Terahertz Schottky to amplify frequency multiplication source, standard terahertz detector uses Thomas thermal detector.And this Terahertz detector to be measured in embodiment include Bolometer detector 3-4 to be measured, Golay detector 3-5 to be measured, Pyroelectricity terahertz detector 3-6 to be measured, Schottky diode 3-7 to be measured, heterodyne terahertz detector 3-8 to be measured. Standard terahertz detector and terahertz detector to be measured are both placed on guide rail 3-3, according to measurement requirement by used Terahertz detector moves into light path.Guide rail 3-3 use Beijing stand upright Han Guang company produce model be RAOB15-1's Product, its stroke is 1.5m.

Low temperature radiometer 3-1 is that Britain NPL develops, and is converted to the signal of telecommunication, uses after its internal cavity absorptive thermal radiation Electricity substituted method achieves power self-calibration, has the absolute response angle value of standard, can measure its receiving plane accurately On terahertz emission value.This low temperature radiometer 3-1 uses helium refrigeration, is operated in the low temperature environment of (5～15) K Under, as the standard detector of weak terahertz signal.

Thomas thermal detector 3-2 is the Terahertz that model is TK100 that Thomas Keating company of Britain produces Detector, has power self-calibration function inside it, have the responsivity value of standard, as the mark of strong terahertz signal Quasi-detector, its technical specification is: probe power is 500mW, NEP to the maximum and is

The feature of Bolometer detector 3-4 to be measured and Golay detector 3-3 to be measured is internal with light cone, is surveying Without Terahertz lens 2-7 during amount, receive the directional light of paraboloidal mirror reflection.Pyroelectricity terahertz detector 3-6 to be measured, The feature of Schottky diode 3-7 to be measured and heterodyne terahertz detector 3-8 to be measured is that inside does not has light cone, therefore is surveying Need Terahertz lens 2-7 to move into light path during amount, terahertz emission is converged on its detection photosurface.

Lock-in amplifier 3-9 selects the SR-830 type product of Stamford company of the U.S., technical specification: frequency range: 1mHz～100KHz, time constant is 30ms, 300ms, 1s, 3s etc., and dynamic memory degree is more than 100dB, and effect is Measurement useful signal is extracted from background noise.

When using Terahertz alternating temperature black matrix 1-1 during measurement, first plane mirror 2-2 is moved into light path, and and center Line placement at 45 °, then the amount of radiation of Terahertz alternating temperature black matrix 1-1 is reflected by plane mirror 2-2, then through chopper blade 2-4 is modulated into periodically variable square wave, incides on off axis paraboloidal mirror 2-6.Use Terahertz Xiao Te when measuring When base amplifies frequency multiplication source 1-2, plane mirror 2-2 removes light path, then Terahertz Schottky amplifies frequency multiplication source 1-2 Amount of radiation, be modulated into periodically variable square wave through chopper blade 2-4 and incide on off axis paraboloidal mirror 2-6.When When detector to be measured inside is without light cone, Terahertz lens 2-7 moves into light path under the control of lens translation stage 2-8. When detector to be measured inside is containing light cone, Terahertz lens 2-7 removes light path under the control of lens translation stage 2-8. Ensure to incide the beam diameter on standard terahertz detector and therewith when measuring by adjusting the bore of iris The corresponding beam diameter on terahertz detector to be measured is identical.

Computer has low temperature radiometer 3-1 with terahertz detector parameter measurement data processing software package, memorizer With the performance number measured on Thomas thermal detector 3-2 receiving plane and and measure used in the process of known parameters, this A little performance numbers include: when Terahertz lens 2-7 removes light path, it is black that low temperature radiometer 3-1 receives Terahertz alternating temperature Performance number P of the directional light that body 1-1 is incident_BB1(Δλ,f)；When Terahertz lens 2-7 moves into light path, low temperature radiometer 3-1 receives performance number P of converging light incident for Terahertz alternating temperature black matrix 1-1_BB2(Δλ,f)；As Terahertz lens 2-7 During removal light path, Thomas thermal detector 3-2 receives Terahertz Schottky and amplifies the incident directional light of frequency multiplication source 1-2 Performance number P_X1(Δ λ, f), when Terahertz lens 2-7 moves into light path, Thomas thermal detector 3-2 receives terahertz Hereby Schottky amplifies performance number P of converging light incident for frequency multiplication source 1-2_X2(Δλ,f)。

Terahertz detector parameter measurement data processing software package includes menu module, Terahertz parameters measurement module, control Molding block, acquisition module, computing module.

The function of described menu module is to show that one group of functional keys, parameter area select menu, parameter over the display Hurdle and display window are set；Functional keys includes that background measures button, detector measurement button, computed push-buttom；Parameter Selecting menu to include with reference to THz source selects menu, Terahertz lens to select menu, Terahertz narrow-band spectrum optical filter Select menu.Wherein, select menu to include two options with reference to THz source, be Terahertz alternating temperature black matrix 1-1 respectively Amplifying frequency multiplication source 1-2 with Terahertz Schottky, this menu selects according to the responding power upper limit of terahertz detector to be measured, When the responding power upper limit of terahertz detector to be measured is less than 10 μ W, select Terahertz alternating temperature black matrix as Terahertz Source；When the responding power upper limit of terahertz detector to be measured is not less than 10 μ W, Schottky is selected to amplify frequency multiplication terahertz Hereby source is as THz source；Terahertz lens select menu to include " use lens " and " not using lens " two options, When detector to be measured is internal Bolometer detector 3-4 to be measured, Golay detector 3-5 to be measured containing light cone, Select " not using lens " option；When detector to be measured is the internal pyroelectricity terahertz detector to be measured without light cone When 3-6, Schottky diode 3-7 to be measured and heterodyne terahertz detector 3-8 to be measured, select " use lens " option. Terahertz narrow-band spectrum optical filter selects menu to include eight options, and i.e. 0, No. 1 Terahertz optical filter, 2 Terahertzs filters Mating plate ... .7 Terahertz optical filter, the peak wavelength of each optical filter is different with spectrum half-band width Δ λ, all corresponding A certain Terahertz narrow band light spectral coverage；The spectral region surveyed is needed to select corresponding sequence number according to terahertz detector to be measured, Having selected rear software to automatically control makes the optical filter of corresponding sequence number move into light path.Wherein No. 0 is through hole, corresponding Terahertz light spectral limit be (30 μm～3000 μm), measure time optical filter runner move on to room.Parameter arranges hurdle For inputting chopper modulating frequency parameter, phase-locked time constant etc..Display window is bent for display background voltage measurement Line, the voltage response experiment curv of tested detector.

Control module be used for controlling translation stage 2-3 and 2-8 make reflecting mirror 2-2 and lens 2-7 move into according to measurement requirement and Removal light path.The function of acquisition module is: when receiving background and measuring button commands, lock-in amplifier exports meter Time dependent voltage signal V on calculation machine_0,j, and in the display window of menu module, show time dependent background Voltage measurement curve；When receiving measurement button commands, lock-in amplifier exports detector measurement electricity on computer Pressure signal V_sUT,j, and in the display window of menu module, show time dependent voltage curve.

Computing module is divided into responsiveness computing module and noise equivalent power computing module, is used for being calculated terahertz to be measured The hereby responsiveness of detector, noise equivalent power NEP, specific detecivity D^*。

Responsiveness computing module function is:

1) for selecting menu setecting " Terahertz alternating temperature black matrix " at THz source, the temperature of Terahertz alternating temperature black matrix is adjusted When joint is to 302.91K, when receiving computed push-buttom instruction, call the merit measured on low temperature radiometer 3-1 test surface Rate value table, the parameter such as responsiveness calculating terahertz detector to be measured according to following set of formula, and at menu module Display window in show the time dependent response curve of tested terahertz detector.

When Terahertz lens 2-7 removes light path, the responsiveness of terahertz detector to be measured uses formula 1,2 to calculate, Formula 3,4 is used to calculate when Terahertz lens 2-7 moves into light path.

$R_{\mathrm{UT}}(\mathrm{\Δ\λ},f)=\frac{\underset{j=1}{\overset{6}{\mathrm{\Σ}}}(V_{\mathrm{sUT},j}-V_{0,j})}{6P_{\mathrm{BB}1}(\mathrm{\Δ\λ},f)}---\left(1\right)$

$P_{\mathrm{BB}1}(\mathrm{\Δ\λ},f)=\frac{6R_{01}(\mathrm{\Δ\λ},f)}{\underset{j=1}{\overset{6}{\mathrm{\Σ}}}(V_{s01,j}-V_{0,j})}---\left(2\right)$

$R_{\mathrm{UT}}(\mathrm{\Δ\λ},f)=\frac{\underset{j=1}{\overset{6}{\mathrm{\Σ}}}(V_{\mathrm{sUT},j}-V_{0,j})}{6P_{\mathrm{BB}2}(\mathrm{\Δ\λ},f)}---\left(3\right)$

$P_{\mathrm{BB}2}(\mathrm{\Δ\λ},f)=\frac{6R_{01}(\mathrm{\Δ\λ},f)}{\underset{j=1}{\overset{6}{\mathrm{\Σ}}}(V_{s01,j}^{\′}-V_{0,j})}---\left(4\right)$

In formula, R_UT(Δ λ, f) for being f in chopper blade rotational frequency, spectrum half-band width is that the terahertz emission of Δ λ measures bar Terahertz detector responsiveness to be measured under part；V_sUT,jThe voltage exported after lock-in amplifier for terahertz detector to be measured Value, V_0,jBackground response signal for the output of liquid nitrogen black matrix.P_BB1(Δ λ f) is black matrix warp when temperature T is 302.91K Become directional light after crossing optical system and incide on low temperature radiometer 3-1, be Terahertz corresponding for Δ λ in spectrum half-band width The performance number of wave band.P_BB2(Δ λ is f) that black matrix becomes converging light after optical system when temperature T is 302.914K Incide on low temperature radiometer 3-1, in the performance number that spectrum half-band width is terahertz wave band corresponding for Δ λ.V_s01,jFor working as The magnitude of voltage that when Terahertz lens 2-7 removes light path, low temperature radiometer 3-1 exports after lock-in amplifier, V '_s01,jFor working as The magnitude of voltage that when Terahertz lens 2-7 moves into light path, low temperature radiometer 3-1 exports after lock-in amplifier.Δ λ is for filtering The half-band width of 1～No. 7 narrow band terahertz band spectral filter in sheet runner, this value is known parameters.R₀₁(Δ λ, f) be Chopper blade rotational frequency is f, spectrum half-band width be Δ λ terahertz emission measuring condition under the mark of low temperature radiometer 3-1 Quasi-responsivity value, this value is the known parameters of low temperature radiometer.

2) for selecting menu setecting " Terahertz Schottky amplifies frequency multiplication source " at THz source, when receiving computed push-buttom During instruction, call Thomas thermal detector 3-2 measure performance number table, according to following set of formula calculate to be measured too The parameters such as the responsiveness of hertz detector, and in the display window of menu module, show tested terahertz detector at any time Between change response curve.

When Terahertz lens 2-7 removes light path, the responsiveness of terahertz detector to be measured uses formula 5,6 to calculate, Formula 7,8 is used to calculate when Terahertz lens 2-7 moves into light path.

$R_{\mathrm{UT}}(\mathrm{\Δ\λ},f)=\frac{\underset{j=1}{\overset{6}{\mathrm{\Σ}}}(V_{\mathrm{sUT},j}-V_{0,j})}{6P_{X1}(\mathrm{\Δ\λ},f)}---\left(5\right)$

$P_{X1}(\mathrm{\Δ\λ},f)=\frac{6R_{02}(\mathrm{\Δ\λ},f)}{\underset{j=1}{\overset{6}{\mathrm{\Σ}}}(V_{s02,j}-V_{0,j})}---\left(6\right)$

$R_{\mathrm{UT}}(\mathrm{\Δ\λ},f)=\frac{\underset{j=1}{\overset{6}{\mathrm{\Σ}}}(V_{\mathrm{sUT},j}-V_{0,j})}{6P_{X2}(\mathrm{\Δ\λ},f)}---\left(7\right)$

$P_{X2}(\mathrm{\Δ\λ},f)=\frac{6R_{02}(\mathrm{\Δ\λ},f)}{\underset{j=1}{\overset{6}{\mathrm{\Σ}}}(V_{s02,j}^{\′}-V_{0,j})}---\left(8\right)$

In formula, P_X1(Δ λ is f) that Terahertz Schottky amplification frequency multiplication source 1-2 becomes directional light incidence after optical system Performance number on Thomas thermal detector 3-2.P_X2(Δ λ is f) that Terahertz Schottky amplifies frequency multiplication source 1-2 process Become converging light after optical system and incide the performance number on Thomas thermal detector 3-2.R₀₂(Δ λ is f) at chopping the light Sheet rotational frequency is f, spectrum half-band width be Δ λ terahertz emission measuring condition under Thomas thermal detector 3-2 Normal response angle value, this value is the known parameters of this detector.V_s02,jFor when Terahertz lens 2-7 removes light path The magnitude of voltage that Thomas thermal detector 3-2 exports after lock-in amplifier, V '_s02,jFor moving into light as Terahertz lens 2-7 The magnitude of voltage that during road, Thomas thermal detector 3-2 exports after lock-in amplifier.

Noise equivalent power computing module, for calculating noise equivalent power NEP of terahertz detector, normalization is visited Survey rate D^*.By close THz source, measure and obtain detector background voltage response value V_0,j.When measuring Select " Terahertz alternating temperature black matrix ", Terahertz alternating temperature black matrix is selected in (103K～353K) temperature range a certain temperature Angle value, measures and obtains responsivity value R of terahertz detector to be measured_UT(Δλ,f)；NEP and D is calculated by following formula^*。

$\begin{array}{cc}\mathrm{NEP}=\frac{\underset{j=1}{\overset{M}{\mathrm{\Σ}}}{V}_{0,j}}{M*R_{\mathrm{UT}}(\mathrm{\Δ\λ},f)}& \left(W\right)\end{array}---\left(9\right)$

$\begin{array}{cc}{D}^{*}=\frac{\sqrt{A\·\mathrm{\Δf}}}{\mathrm{NEP}}& (\mathrm{cm}\·\sqrt{\mathrm{Hz}}/*W)\end{array}---\left(10\right)$

In formula, A is terahertz detector to be measured area of receiving plane when measuring, and Δ f is measuring circuit bandwidth.

In the present embodiment, terahertz detector measurement method of parameters is as follows:

The method includes two parts: the parameter measurement sides such as terahertz detector responsiveness measuring method, noise equivalent power Method.

1, weak terahertz detector responsiveness measuring process:

1) electronic control translation stage 2-3 and 2-8 power supply, the on and off switch of computer 4 are opened；When terahertz detector to be measured The responding power upper limit less than 10 μ W time, open computer software, THz source select menu setecting " Terahertz become Temperature black matrix ".When detector to be measured be internal containing light cone time Bolometer detector 3-4 to be measured, Golay to be measured visit When surveying device 3-5, select the menu setecting option that " do not uses lens " at Terahertz lens, then Terahertz lens 2-7 removes light Road；Now, low temperature radiometer 3-1 is moved into light path, the directional light center that paraboloidal mirror is just being reflected by its center.? Terahertz narrow-band spectrum optical filter selects the through hole in menu setecting 0 option, i.e. optical filter runner to move on to light path position, The radiation of all terahertz wave bands that Terahertz alternating temperature black matrix 1-1 sends all is detected system and receives.

2) fill liquid nitrogen to liquid nitrogen refrigerating black matrix 1-3, open molecular pump 2-12 on and off switch, to vacuum background channel 2-10 evacuation, until vacuum reaches 10^-4mbar.Then by liquid nitrogen hand-hole 2-11 to vacuum background channel 2-10 In outside sandwich inside fill liquid nitrogen.After using molecular pump 2-12 to low temperature radiometer 3-1 evacuation, to low temperature simultaneously Radiometer 3-1 is internal is full of helium, it is ensured that its work is at low ambient temperatures.

3) open chopper controller 2-5, lock-in amplifier 3-6, the on and off switch of low temperature radiometer 3-1, make chopping the light Sheet 2-4 rotates with fixing frequency, and the time constant of lock-in amplifier 3-9 is set to 30ms.Adjust iris The bore of 2-9 ensures the beam diameter on incident standard terahertz detector and corresponding terahertz detection to be measured The beam diameter of device is identical.

4) clicking on background on computer software and measure button, when chopper blade 2-4 rotates, chopper blade 2-4 is with specific Frequency the radiation of background radiation and liquid nitrogen refrigerating black matrix 1-3 is replaced with fixed frequency, be input to lock-in amplifier 3-9 Receiving, lock-in amplifier 3-9 exports background radiation voltage signal V_0,jTo computer, measure 6 times, and store.

5) open Terahertz alternating temperature black matrix 1-1 on and off switch, its temperature is adjusted to 302.91K, after preheating 30 minutes, Computer software is clicked on detector measurement button, the radiation of Terahertz alternating temperature black matrix 1-1 and liquid nitrogen refrigerating black matrix 1-3 Radiation incide low temperature radiometer with fixed frequency alternately across becoming directional light after the optical system of apparatus of the present invention On 3-1, be converted to the signal of telecommunication by reception, by lock-in amplifier 3-9 output voltage values, this magnitude of voltage Input Software counted Calculate the terahertz emission performance number obtaining receiving, and store.

6) low temperature radiometer 3-1 is removed light path, Bolometer detector 3-4 or to be measured Golay to be measured is detected Device 3-5 moves into light path, opens detector switch to be measured, clicks on and measure button, finally by phase-locked on computer software Amplifier 3-9 output voltage measures signal V_sUT,j, measure 6 times, and store.

7) clicking on computed push-buttom, software automatically calls the formula in computing module and calculates the responsiveness ginseng of detector to be measured Number.

8) selecting menu setecting i option at Terahertz narrow-band spectrum optical filter, i is from 1 to 7, then optical filter runner rotates, 1-7 Terahertz optical filter is made to be sequentially placed in light path.Then measuring by above-mentioned 5-7 step, software calls meter automatically Calculate the responsiveness of terahertz detector difference Terahertz narrow-band scope to be measured.

9) it is internal without the pyroelectricity terahertz detector 3-6 to be measured of light cone, Schottky to be measured two when detector to be measured During pole pipe 3-7 and heterodyne terahertz detector 3-8 to be measured, select " use lens " option, then lens move into light path.So After repeat above-mentioned 5-8 step, obtain the responsiveness parameter of above-mentioned three kinds of terahertz detectors.

2, strong terahertz detector responsivity measuring process:

1) when the responding power upper limit of terahertz detector to be measured is more than 10 μ W, computer software is opened, at terahertz Hereby source selects menu setecting " Schottky amplifies frequency multiplication THz source ", plane mirror reflects 2-2 and removes light path, by Thomas Thermal detector 3-2 moves into light path, and opens detector switch.The bore adjusting iris 2-9 ensures incident Thomas Beam diameter on thermal detector is identical with the beam diameter of corresponding terahertz detector to be measured.At computer On software click on background measure button, when chopper blade 2-4 rotates, chopper blade 2-4 with specific frequency background spoke Penetrate the radiation with liquid nitrogen refrigerating black matrix 1-3 to replace with fixed frequency, be input to lock-in amplifier 3-9 and receive, phase-locked put Big device 3-9 exports background radiation voltage signal V_0,jTo computer 4, measure 6 times, and store.

2) open Schottky and amplify frequency multiplication THz source 1-2 on and off switch, after preheating 10 minutes, at computer software Upper click detector measurement button, Schottky amplifies the radiation of frequency multiplication THz source 1-2 and liquid nitrogen refrigerating black matrix 1-3 Radiation incides Thomas hot-probing with fixed frequency alternately across becoming directional light after the optical system of apparatus of the present invention On device 3-2, being converted to the signal of telecommunication by reception, by lock-in amplifier 3-9 output voltage values, this magnitude of voltage is input to meter On calculation machine 4 software, it is calculated terahertz emission performance number, and stores.

3) Thomas thermal detector 3-2 is removed light path, Golay detector 3-5 to be measured is moved into light path, opens Detector switch to be measured, clicks on computer software and measures button, finally surveyed by lock-in amplifier 3-9 output voltage Amount signal V_sUT,j, measure 6 times, and store.

4) clicking on computed push-buttom, software automatically calls the formula in computing module and calculates the responsiveness ginseng of detector to be measured Number.

5) it is internal without the pyroelectricity terahertz detector 3-6 to be measured of light cone, Schottky to be measured two when detector to be measured During pole pipe 3-7 and heterodyne terahertz detector 3-8 to be measured, select " use lens " option, then lens move into light path.So Rear repeat the above steps, obtains the responsiveness parameter of above-mentioned three kinds of terahertz detectors.

3, terahertz detector noise equivalent power measuring process:

1) clicking on background on computer software and measure button, when chopper blade 2-4 rotates, chopper blade 2-4 is with specific Frequency the radiation of background radiation and liquid nitrogen refrigerating black matrix 1-3 with fixed frequency alternately across the optics of apparatus of the present invention Become directional light after system to incide on low temperature radiometer 3-1, be converted to the signal of telecommunication by reception, be input to phase-locked amplification Device 3-9 receives, and lock-in amplifier 3-9 exports background radiation voltage signal V_0,jTo computer, measure 6 times, and store.

2) select menu setecting " Terahertz alternating temperature black matrix " at THz source, select dish at Terahertz narrow-band spectrum optical filter The through hole that single choice is selected in 0 option, i.e. optical filter runner moves on to light path position, all terahertz wave bands that black matrix sends Radiation is all detected system and receives.A certain temperature is selected in (103K～353K) temperature range of Terahertz alternating temperature black matrix Angle value, measures and obtains responsivity value R of terahertz detector_UT(Δλ,f)。

3) click on " calculating " button, obtain noise equivalent power value and normalized detectivity value D of this detector to be measured^*。

4) Terahertz narrow-band spectrum optical filter select menu select i option one by one, i from 1 to 7, then optical filter runner Rotate, make 1-7 Terahertz optical filter be sequentially placed in light path.Then measuring by above-mentioned steps, software calls automatically Calculate noise equivalent power value and the normalized detectivity value of different Terahertz narrow-band scope.

Claims (7)

1. a terahertz detector parameter measuring apparatus, it is characterised in that: include light-source system, optical system, detection System and data processing module；Described light-source system includes with reference to THz source, low-temp radiating black matrix；Optical system System includes that terahertz emission is modulated into the chopper blade of cyclically-varying square wave, is parallel by terahertz emission collimation The off axis paraboloidal mirror of light, iris, vacuum and low temperature background channel；Detection system includes that standard Terahertz is visited Survey device, terahertz detector to be measured and lock-in amplifier；

In light-source system, optical system, the miscellaneous part except vacuum and low temperature background channel all leads in vacuum and low temperature background In road；The luminous position of reference THz source and low-temp radiating black matrix is all in the focus of off axis paraboloidal mirror；Chopping the light Sheet is positioned in the light path of light-source system and off axis paraboloidal mirror, and chopper blade rotates according to setpoint frequency, alternately will be with reference to too The radiation signal in hertz source introduces light path with the radiation reference signal of low-temp radiating black matrix；The outgoing of off axis paraboloidal mirror is put down Row light injects iris, and iris realizes injecting standard terahertz detector and the light beam of terahertz detector to be measured Aperture is identical；The output signal of standard terahertz detector and terahertz detector to be measured inputs to through lock-in amplifier Data processing module；

Optical system also includes movably for assembling the Terahertz lens of terahertz emission, when terahertz to be measured When hereby detector inside is without light cone, Terahertz lens move in the light path between off axis paraboloidal mirror and iris.

A kind of terahertz detector parameter measuring apparatus, it is characterised in that: with reference to Terahertz Source is divided into for providing the Terahertz alternating temperature black matrix of weak terahertz emission and for providing the terahertz of strong terahertz radiation Hereby Schottky amplifies frequency multiplication source；Standard terahertz detector is divided into low temperature radiometer and Thomas thermal detector；When When using Terahertz alternating temperature black matrix with reference to THz source, standard terahertz detector uses low temperature radiometer, reference When THz source uses Terahertz Schottky to amplify frequency multiplication source, standard terahertz detector uses Thomas hot-probing Device；Optical system includes moveable plane mirror, and plane mirror controls Terahertz alternating temperature as required Black matrix or Terahertz Schottky amplify frequency multiplication source and enter light path.

A kind of terahertz detector parameter measuring apparatus, it is characterised in that: when terahertz to be measured When hereby the responding power upper limit of detector is less than 10 μ W, use Terahertz alternating temperature black matrix with reference to THz source, when When the responding power upper limit of terahertz detector to be measured is not less than 10 μ W, use Terahertz Xiao with reference to THz source Te Ji amplifies frequency multiplication source.

A kind of terahertz detector parameter measuring apparatus, it is characterised in that: in optical system Also including optical filter runner, optical filter runner, with reference in the light path between THz source and chopper blade, filters Sheet runner includes the optical filter of multiple corresponding different Terahertz narrow band light spectral coverages.

A kind of terahertz detector parameter measuring apparatus, it is characterised in that: low-temp radiating is black Body uses liquid nitrogen refrigerating black matrix, and vacuum and low temperature background channel housing is divided into two-layer, by note between housing ectonexine Entering liquid nitrogen refrigerating, vacuum and low temperature background channel vacuum is at least up to 10^-4mbar。

6. one kind utilizes the method that device described in claim 1 carries out terahertz detector parameter measurement, it is characterised in that:

Employing following steps:

Step 1: close with reference to THz source, chopper blade with frequency f by the background radiation of vacuum and low temperature background channel and The radiation of low-temp radiating black matrix is alternatively introduced into light path, standard terahertz detector receive, and obtained by lock-in amplifier Background radiation voltage signal V_0,j, j=1,2 ..., M, M are pendulous frequency；

Step 2: opening with reference to THz source, chopper blade will be black with reference to THz source radiation and low-temp radiating with frequency f The radiation of body is alternatively introduced into light path, standard terahertz detector receive, and obtained voltage signal by lock-in amplifier V_01,j；

Step 3: standard terahertz detector is removed light path, moves into light path by terahertz detector to be measured；Chopper blade With frequency f by being alternatively introduced into light path with reference to the radiation of THz source radiation and low-temp radiating black matrix, Terahertz to be measured visit Survey device receives, and is obtained voltage signal V by lock-in amplifier_sUT,j；

Step 4: obtain terahertz detector to be measured at the terahertz that frequency f, spectrum half-band width are Δ λ by below equation Hereby responsiveness R under the conditions of actinometry_UT(Δ λ, f):

$R_{UT}(\mathrm{\Δ}\mathrm{\λ},f)=\frac{\underset{j=1}{\overset{M}{\Σ}}(V_{sUT,j}-V_{0,j})}{M*P_{BB}(\mathrm{\Δ}\mathrm{\λ},f)},P_{BB}(\mathrm{\Δ}\mathrm{\λ},f)=\frac{M*R_{01}(\mathrm{\Δ}\mathrm{\λ},f)}{\underset{j=1}{\overset{M}{\Σ}}(V_{01,j}-V_{0,j})}$

Wherein R₀₁(Δ λ is f) standard terahertz detector at the terahertz emission measuring condition that frequency f, spectrum half-band width are Δ λ Under responsivity value；Obtain noise equivalent power NEP of terahertz detector to be measured by below equation, normalization is visited Survey rate D^*:

$NEP=\frac{\underset{j=1}{\overset{M}{\Σ}}{V}_{0,j}}{M*R_{UT}(\mathrm{\Δ}\mathrm{\λ},f)},D^{*}=\frac{\sqrt{A\·\mathrm{\Δ}f}}{NEP}$

Wherein A is the area of terahertz detector receiving plane to be measured, and Δ f is measuring circuit bandwidth.

A kind of terahertz detector measurement method of parameters, it is characterised in that: when terahertz to be measured When hereby detector is the responding power upper limit weak terahertz detector less than 10 μ W, use too with reference to THz source Hertz alternating temperature black matrix, standard terahertz detector uses low temperature radiometer；When terahertz detector to be measured is response When power upper limit is not less than the strong terahertz detector of 10 μ W, Terahertz Schottky is used to put with reference to THz source Big frequency multiplication source, standard terahertz detector uses Thomas thermal detector.