CN208780341U - A kind of diffraction element and high resolution spectrometer - Google Patents

Abstract

The utility model relates to light spectrum detecting apparatus field, a kind of diffraction element and high resolution spectrometer are disclosed.Light source to be measured is incident on the diffraction element of the spectrometer in parallel by collimation lens, the diffraction element is made of multiple diffraction grating units, the indentation Density Distribution and/or indentation inclined direction of the diffraction grating unit are different, random scattering occurs after the diffraction element for light to be measured, pass through speckle pattern of the image recording sensor light to be measured at Zero-order diffractive and at first-order diffraction, the speckle pattern is compared with wavelength-speckle pattern java standard library by spectroscopic analysis system again, the anti-spectroscopic data for releasing light to be measured.The spectrometer architecture of the utility model is simple, has a high-resolution, and it is artificial it is controllable, can be produced in batches, while it is small, easy to operate using the spectrometer to carry out spectral detection error, is with a wide range of applications.

Description

A kind of diffraction element and high resolution spectrometer

Technical field

The utility model relates to light spectrum detecting apparatus fields, and in particular to a kind of diffraction element and high resolution spectrometer.

Background technique

Spectrometer is a kind of instrument for parsing light source medium wavelength composition and relative intensity relationship, it has had upper a century Developing history.Traditional spectrometer be composite light source is separated according to wavelength order using the dispersion elements such as prism, grating, then It is measured using Wavelength scanning mechanism and detector.Current most popular spectrometer architecture is using Czerny-Turner type Optical path, it includes entrance slit, collimating mirror, grating, focus lamp, exit slit and detector.This spectrometer resolution ratio takes It is certainly horizontal in the adjusting of grating dispersion ability, the focal length of focus lamp, slit width and optical path.Typically, it to obtain preferably Resolution ratio, slit narrow as far as possible is generally required, but the light energy that will lead in this way into instrument substantially reduces, to will affect The measurement efficiency and signal-to-noise ratio of instrument.In this kind of spectrometer, some wavelength can be mapped to one by dispersion element (grating, prism) A specific imaging point.For using sensor arrays such as CCD as the spectrometer of detector, formed between wavelength and CCD pixel A kind of mapping relations one by one.Therefore, the wavelength analysis feature of spectrometer depends primarily on hardware (optical path, grating, detector etc.) Performance, in other words, spectrometer is very high to hardware requirement.

In recent years, a kind of novel spectral method of detection that the random scattering phenomenon using Random Media constructs obtains rapidly Development, is known as and calculates spectrometer (computational spectrometer).For example, Yale University Cao Hui is studied Team proposes to constitute spectral measurement device in the randomness of multimode fibre multiple reflection inside using light, each monochromatic wavelength The speckle pattern that is formed after fiber exit of light be different from, and even if wavelength interval very little two monochromatic light, they Correlation between speckle pattern is also very low, thus the characteristics of can use this wavelength low related speckle pattern carrys out counter be pushed into and penetrates The Wavelength components of light.For another example, the Mennon R of Univ Utah USA is proposed using the disordered chain of phase directional scatter come real Existing spectral detection.It also utilizes this feature of the low wavelength dependence of random medium scattering pattern, to realize to incident light The spectral detection purpose in source.Due to dispersive power and size of the resolution ratio independent of optical element of such spectrometer, but Randomness and software dependent on medium calculate, thus this spectrometer is expected to overcome the contradiction of instrument size and resolution ratio, has Prestige obtains high-resolution micro spectrometer.

But above-mentioned technology depends on the natural randomness of medium, this randomness is uncontrollable, and then leads to light Spectrum detects two spectrum that the correlation between random scattering pattern can not be controlled, therefore be manufactured according to same principle Instrument has different parameters, and difference may also be had in performance, requires to recalibrate to every set system, model again, institute Accomplish standardized production to have no idea.In addition to this, although the Mennon R professor of Univ Utah USA is random using phase Width of nick difference in grating realizes the disordered chain of light to be measured, but this method is higher in actual fabrication process difficulty, carves Trace depth accuracy of repetition is difficult to ensure, therefore is also not suitable for mass production.

Utility model content

In order to solve the above technical problems, the purpose of the utility model is to provide the diffraction that one kind can form different speckle patterns The spectrometer that element and a kind of structure simply have high-resolution and artificially can controllably be produced in batches.

A kind of in order to achieve the above object, the utility model provides diffraction element, comprising:

Substrate and the multiple diffraction grating units being engraved on the substrate, by the quarter for changing the diffraction grating unit The inclined direction of trace Density Distribution and/or the indentation so that the monochromatic light of different wave length from the diffraction element outgoing after shape At speckle pattern it is different.

The utility model additionally provides a kind of high resolution spectrometer, including diffraction element as described above, and,

Incident unit, the incidence unit include the light and collimation lens to be measured that light source to be measured issues；And

Random scattering occurs in the diffraction element for the light to be measured, is formed after outgoing in the diffraction element side Speckle pattern；And

For recording the imaging sensor of the speckle pattern；And

Spectroscopic analysis system for comparing the obtained speckle pattern and wavelength-speckle pattern java standard library, wherein There are the monochromatic light of different wave length and the mapping relations number of corresponding diffraction speckle pattern in the wavelength-speckle pattern java standard library According to.

Further, the diffraction element includes array of diffraction gratings, wherein indentation density in monolithic diffraction grating unit It is identical to be distributed identical and indentation inclined direction, and the indentation Density Distribution difference of any two pieces of diffraction grating units and indentation inclination Direction is different.

Further, the speckle at the speckle pattern and first-order diffraction at described image sensor record at least Zero-order diffractive Pattern.

Further, the spectroscopic analysis system includes,

Signal acquisition unit, the signal acquisition unit and described image sensor couple, and pass for receiving described image The speckle pattern data of sensor output；And

With the signal processing unit of signal acquisition unit coupling, the signal processing unit from the signal for adopting Collection unit obtains the speckle pattern data and is divided the speckle pattern data and the wavelength-speckle pattern java standard library Analysis compares；And

For storing the wavelength-speckle pattern java standard library cache unit, the cache unit, which has, to be equaled or exceeded The wavelength-speckle pattern java standard library size memory space；And

For exporting the output unit of the smooth Spectroscopic analysis results to be measured.

Further, the diffraction grating unit is obtained by laser interference and spot scan method, subsequent to pass through molding It is prepared by the method for duplication.

Further, the substrate of the substrate of the collimation lens and the diffraction element is optical glass or the organic glass of optics Glass.

Further, the light source to be measured is located at the focal position of the collimation lens.

Further, described image sensor is CCD photosensitive element or CMOS photosensitive element.

The utility model additionally provides a kind of spectral method of detection, is examined using high resolution spectrometer as described above It surveys, comprising the following steps:

S1, the incident high resolution spectrometer of monochromatic light using different wave length, construct wavelength-speckle pattern standard Library；

S2, the speckle by image recording sensor light to be measured at Zero-order diffractive after diffraction element and at first-order diffraction Pattern；

S3, it spectroscopic analysis system acquisition, analyzes the speckle pattern and exports the spectroscopic data of the light to be measured.

Further, in step S3, the speckle pattern is analyzed method particularly includes:

If Sa1, light to be measured are monochromatic light, by the number in the speckle pattern and the wavelength-speckle pattern java standard library According to being compared, corresponding related coefficient is calculated；

If Sa2, the related coefficient are greater than or equal to screening threshold value, the wavelength of the light to be measured is equal to the phase relation Known wavelength in the corresponding java standard library of number, exports result by output module；

If Sa3, the related coefficient are less than the screening threshold value, expand Wavelength calibration range, returns to S1 and rebuild Wavelength-speckle pattern java standard library；

If Sb1, light to be measured are polychromatic light, by the data in the speckle pattern and the wavelength-speckle pattern java standard library It is approximate to carry out linear combination, calculates optimum linear combination；

Sb2, the light to be measured spectral component be corresponding wavelength components in optimum linear combination, and by output mould Block exports result.

In the utility model, random scattering occurs in diffraction element for light to be measured, records the diffraction speckle of light to be measured Pattern, comparing with wavelength-speckle pattern java standard library can the rapidly and accurately anti-spectroscopic data for releasing light to be measured；And it constitutes and spreads out The diffraction grating for penetrating unit is easy duplication preparation, so as to preferably control the correlation between speckle pattern；In addition to this, should Spectrometer architecture is simple, and manufacturing cost small to the dependence of hardware is low, therefore is with a wide range of applications.

Detailed description of the invention

In order to illustrate more clearly of the technical solution in the utility model embodiment technology, embodiment technology will be retouched below Attached drawing needed in stating is briefly described, it should be apparent that, the accompanying drawings in the following description is only the utility model Some embodiments for those of ordinary skill in the art without creative efforts, can also basis These attached drawings obtain other attached drawings.

Fig. 1 is the structural schematic diagram of the preferred embodiment in the utility model；

Fig. 2 is the spectroscopic analysis system structural schematic diagram of embodiment described in Fig. 1；

Fig. 3 is the step flow chart using the spectral method of detection of embodiment described in Fig. 1.

Each symbol is expressed as follows in figure:

1, light source to be measured, 2, collimation lens, 3, diffraction element,

4, diffraction grating unit, the 5, the first CCD, the 6, the 2nd CCD

Specific embodiment

The following will be combined with the drawings in the embodiments of the present invention, carries out the technical scheme in the embodiment of the utility model Clearly and completely describe, it is clear that the described embodiments are only a part of the embodiments of the utility model, rather than whole Embodiment.Based on the embodiments of the present invention, those of ordinary skill in the art are without creative efforts Every other embodiment obtained, fall within the protection scope of the utility model.

Embodiment

Referring to 1~attached drawing of attached drawing 3, the preferred embodiment spectrometer of the utility model includes incident unit, diffraction element, figure As four parts of sensor and spectroscopic analysis system.

Incident unit includes the incident light and collimation lens 2 to be measured of light source 1 to be measured, and the collimated lens 2 of light to be measured collimate It is incident on diffraction element 3 in parallel with unspecified angle in 0~90 ° afterwards；Diffraction element 3 is the array of diffraction gratings of 200x200, In, the width of nick of each diffraction grating unit 4 is identical, and 4 inside indentation Density Distribution of monolithic diffraction grating unit is identical and carves Trace inclined direction is identical, and indentation Density Distribution difference and/or indentation inclined direction between any two pieces of diffraction grating units 4 Difference, the Pixel Dimensions of diffraction grating unit 4 are 100 μm of 100 μ m；At this point, light to be measured occur in diffraction element 3 it is random Scattering, if light to be measured is monochromatic light, the diffraction speckle pattern that the light of each monochromatic wavelength is formed after the outgoing of diffraction element 3 Be different from, and even if wavelength interval very little two monochromatic light, the correlation between their speckle patterns is also very low, thus The characteristics of can use this wavelength low related speckle pattern counter to be pushed into the Wavelength components for penetrating light to be measured；After diffraction element 3 Several imaging sensors are set at the optical diffraction position to be measured of 10cm, record the speckle pattern of light to be measured；Speckle pattern is by spectrum It is compared after signal acquiring system acquisition in analysis system with the wavelength-speckle pattern java standard library being stored in cache unit And correlation is calculated by signal processing unit, with this come the anti-spectroscopic data for releasing light to be measured, wherein the wavelength-speckle There are the monochromatic light of different wave length and the mapping relations data of corresponding diffraction speckle pattern in pattern standards library, finally by exporting Unit exports result.

The utility model first has to carry out the calibration of wavelength-speckle pattern java standard library to spectrometer when in use.It is collimating The focal point of lens 2 places light source generator, and adjustment wave-length coverage makes it issue the monochromatic light of different wave length, in diffraction element 3 Zero-order diffractive at and first-order diffraction at place the first CCD5 and the 2nd CCD6 respectively, record corresponding speckle pattern, pass through light Spectrum analysis is system converting to be stored in cache unit at corresponding spectroscopic data, and the monochromatic light pair of the wave-length coverage is constructed with this The wavelength answered-speckle pattern java standard library.

Carrying out spectral detection using the present embodiment spectrometer, the specific method is as follows:

S1, the incident high resolution spectrometer of monochromatic light using different wave length, construct wavelength-speckle pattern standard Library；

S2, the light to be measured is recorded at the Zero-order diffractive after diffraction element by the first CCD and the 2nd CCD spread out with level-one Penetrate the speckle pattern at place；

S3, it spectroscopic analysis system acquisition, analyzes the speckle pattern and exports the spectroscopic data of the light to be measured.

Wherein, the speckle pattern is analyzed in S3 method particularly includes:

If Sa1, light to be measured are monochromatic light, by speckle pattern and it is stored in cache unit by signal processing unit Wavelength-speckle pattern java standard library is compared, and calculates corresponding correlation coefficient r；

If Sa2, r >=0.7, the wavelength of light to be measured is equal to the known wavelength in the corresponding java standard library of correlation coefficient r, by defeated Module exports result out；

If Sa3, r < 0.7, expand Wavelength calibration range, returns to S1 and rebuild wavelength-speckle pattern java standard library；

If Sb1, light to be measured are polychromatic light, the data in speckle pattern and wavelength-speckle pattern java standard library are subjected to line Property combination approximation, calculate optimum linear combination；

Sb2, light to be measured spectral component be corresponding wavelength components in optimum linear combination, and exported by output module As a result.

By allowing light to be measured that random scattering occurs in diffraction element, the diffraction for recording light to be measured dissipates the utility model Spot pattern, comparing with wavelength-speckle pattern java standard library can the rapidly and accurately anti-spectroscopic data for releasing light to be measured；Diffraction grating The substrate of unit can be selected optical glass or optics organic glass and be prepared by laser interference and spot scan method, after It is continuous to carry out batch duplicating by mould pressing method, to preferably control the correlation between spectral detection speckle pattern；Except this Except, the spectrometer architecture is simple, and manufacturing cost small to the dependence of hardware is low, therefore is with a wide range of applications.

The foregoing description of the disclosed embodiments can be realized professional and technical personnel in the field or using originally practical new Type.Various modifications to these embodiments will be readily apparent to those skilled in the art, and determine herein The General Principle of justice can be realized in other embodiments without departing from the spirit or scope of the present utility model.Cause This, the present invention will not be limited to the embodiments shown herein, and is to fit to and principles disclosed herein The widest scope consistent with features of novelty.

Claims (6)

1. a kind of diffraction element, including substrate and the multiple diffraction grating units being engraved on the substrate, it is characterised in that: single Indentation Density Distribution is identical in block diffraction grating unit and indentation inclined direction is identical, and the quarter of any two pieces of diffraction grating units Trace Density Distribution is different and/or indentation inclined direction is different.

2. a kind of high resolution spectrometer, including diffraction element as described in claim 1, which is characterized in that further include:

Incident unit, the incidence unit include the light and collimation lens to be measured that light source to be measured issues；

Random scattering occurs in the diffraction element for the light to be measured, forms speckle in the diffraction element side after outgoing Pattern；And

For recording the imaging sensor of the speckle pattern；And

Spectroscopic analysis system for comparing the obtained speckle pattern and wavelength-speckle pattern java standard library, wherein described There are the monochromatic light of different wave length and the mapping relations data of corresponding diffraction speckle pattern in wavelength-speckle pattern java standard library.

3. high resolution spectrometer according to claim 2, it is characterised in that: described image sensor record at least zero level The speckle pattern at speckle pattern and first-order diffraction at diffraction.

4. high resolution spectrometer according to claim 2, it is characterised in that: the spectroscopic analysis system includes,

Signal acquisition unit, the signal acquisition unit and described image sensor couple, for receiving described image sensor The speckle pattern data of output；And

With the signal processing unit of signal acquisition unit coupling, the signal processing unit is used for from the signal acquisition list Member obtains the speckle pattern data and the speckle pattern data and the wavelength-speckle pattern java standard library is carried out analysis ratio It is right；And

For storing the wavelength-speckle pattern java standard library cache unit, the cache unit is described with equaling or exceeding Wavelength-speckle pattern java standard library size memory space；And

For exporting the output unit of the smooth Spectroscopic analysis results to be measured.

5. high resolution spectrometer according to claim 2, it is characterised in that: it is saturating that the light source to be measured is located at the collimation At the focal position of mirror.

6. high resolution spectrometer according to claim 2, it is characterised in that: described image sensor is the photosensitive member of CCD Part or CMOS photosensitive element.