CN203216609U - A spectrograph - Google Patents

Abstract

The utility model discloses a spectrograph and belongs to the field of optical measurement technology. The spectrograph comprises an optical alignment device, a light splitting component, and an array detection chip, which are arranged in order in incident direction of a light path. The spectrograph also comprises a data collection and analysis system connected with the array detection chip. The light splitting component comprises a transparent substrate; at least one layer of transparent coating is fixed on at least one surface of the transparent substrate; and the transparent coating contains a group of bubbles with non-uniform sizes or shapes. Compared with the conventional spectrograph, the spectrograph provided by the utility model has the advantages of low cost, portability, higher resolution ratio and wider spectral measurement range.

Description

A kind of spectrometer

Technical field

The utility model relates to spectral measurement device, relate in particular to a kind of have high resolving power and wide measurement range, but the spectrometer of portable real-time detection belongs to field of optical measuring technologies.

Background technology

Spectrometer is a kind of important optical instrument.It is that optical means is combined with the hyundai electronics data handling system, and the spectral information of studying material by obtaining comes the basic equipment of structure, composition and the content of Accurate Analysis material.Along with the development of spectrometer, its range of application is more and more wider, and has contained a plurality of fields, as astronomical sight, Aero-Space, biological medicine, petrochemical complex, modern agriculture, metallurgy, geologic prospecting, ecologic environment and national defense and military etc.Because its important use is worth, spectrometer more and more is subjected to people's attention, and it has become the important component part of Modern Scientific Instruments.

Yet, along with progress and the rapid development of science and technology of society, in a lot of fields spectrometer is had higher requirement again.Particularly in numerous researchs, applications such as spaceborne analysis, geological and mineral exploration, spacer remote sensing remote measurement, environmental monitoring, micro-fluidic fields, measuring under the situation that frequency range is wide, resolution is high, vibration and interference resistance is strong, stable and reliable for performance, need a kind of microminiaturization, integrated, intelligentized spectrometer.Its power consumption is little, voltage is low, easy to use flexibly, the ratio of performance to price is high, and can obtain spectral signal fast, in real time, intuitively.And at present the widely used spectrometer of institute not only resolution is not high enough, it is wide inadequately to measure frequency band, and deficiencies such as the ubiquity volume is big, expensive, Installation and Debugging are difficult, service condition harshness.Not only volume is bigger as Fourier transform spectrometer,, and to vibration sensing, its resolution is subjected to the influence of the moving range of index glass.Though the used grating volume of optical grating diffraction type spectrometer is less relatively, but this kind spectrometer resolution is not high, and expensive [Yang Jae-chang, et al.Micro-electro-mechanical-systems-based infrared spectrometer composed of multi-slit grating and bolometer array, Jap.J.of Appl.Phys.47 (8), 6943-6948 (2008)].

It is the patent documentation of 200910264251.X that application number has been authorized on September 26th, 2012 by State Intellectual Property Office of the People's Republic of China, title is " phase modulation stepped array micro-spectrograph ", and its core component is the two-dimensional stepped array that is structured on CCD or the CMOS.Disclosing publication number on July 11st, 2012 is the patent documentation of CN102564586A, title is " opening diffracting array structure micro spectrometer and high-resolution spectroscopy restored method thereof ", and its core component is the two-dimentional opening diffracting array that is structured on CCD or the CMOS.Owing to after the light of different wave length passes through step or opening diffracting, can produce different interference or diffraction intensity in the pixel elements of CCD or CMOS.Therefore can just can utilize the method for finding the solution large-scale system of linear equations to restore spectrum by measuring the luminous power of different big small stairs or next series of pixels unit of opening diffracting.Compare with traditional grating spectrograph or Fourier transform spectrometer,, its volume is little, frequency resolution is high, spectral measurement ranges is wide, can realize static measurement in real time.But no matter be spectrometer ledge structure or the opening diffracting structure, its cost of manufacture is higher, and complex manufacturing process need be used expensive equipment, such as ion etching system or lithographic equipment etc.Therefore, need seek that cost is lower, the simple array structure micro spectrometer of manufacturing process method for making.

The utility model content

Technical problem to be solved in the utility model is: under the prerequisite that keeps existing array structure micro spectrometer performance, overcome that the existing cost of manufacture of the micro spectrometer of array structure described in the background technology is higher, the problem of complex manufacturing process, the spectrometer that a kind of making is simpler, cost is cheaper is provided.

Spectrometer of the present utility model, comprise the optical alignment device, light-splitting device, the array detection chip that set gradually along the light path incident direction, and the data collection and analysis system that is connected with described array detection chip, described light-splitting device comprises transparent substrates, set is gone up at least one surface of described transparent substrates one deck clear coat at least, includes the bubble of a packet size or shape uneven distribution in the described clear coat.Described clear coat is preferably polymkeric substance.

As a preferred version of the present utility model, described light-splitting device prepares in accordance with the following methods: inert gas is passed into generates the inert gas bubble in the polymer melt, and by ultrasound wave the inert gas bubble is carried out refinement; Treat in the polymer melt air bubble content and distribution level off to stable after, polymer melt is coated on the transparent substrates, cooling forms polymer coating.

As another preferred version of the present utility model, described light-splitting device prepares in accordance with the following methods: polymkeric substance is dissolved in the organic solvent, forms polymer solution; After polymer solution makes it to produce bubble under stirring, polymer solution is coated in the transparent substrates surface; Then, remove the organism solvent by heating, form polymer coating.

Preferably, described optical alignment device comprises two confocal lens, and the aperture that is arranged at the common focus place of described two lens.

The utility model utilizes the clear coat that has transparent bubble to replace ledge structure or the opening diffracting structure of complex manufacturing technology on the basis of existing array structure micro spectrometer.Compared to existing technology, the utlity model has following beneficial effect:

1, manufacture craft is simple, and cost is lower.Micro spectrometer in the past need be used methods such as ion etching or photoetching at substrate making step or opening diffracting, these methods need expensive equipment, and complex process, need accurately to control the size of step or opening diffracting, and make that the position of step or opening diffracting is corresponding one by one with the position of pixel elements.

2, the spectrometer volume is little, is easy to carry, and does not need the mobile optical device during measurement, and vibration factor is less to its influence, is used in the real-time measurement in the complex environment.

3. spectrometer has higher resolution and wideer spectral measurement ranges.The resolution of spectrum is mainly determined by the quantity of detection array chip CCD or cmos pixel unit, and the pixel of these detection array chips can reach more than 1,000,000, so whole spectral measurement device can reach very high frequency resolution; The spectral range that the detection array chip can detect has determined the spectral measurement width, and its spectral measurement ranges has covered can see infrared band, and even ultraviolet band, therefore should wideer spectral measurement ranges can be arranged spectrometer mutually.

Description of drawings

Fig. 1 is the cross sectional representation of the utility model spectrometer, and wherein, 1 is clear coat, and 2 is transparent substrates, and 3 is that array detection chip, 4 is that lens, 5 are aperture;

Fig. 2 is the surperficial vertical view of clear coat 1, and wherein, 6 is bubble;

Fig. 3 is incident light spectrum division methods synoptic diagram; Wherein, horizontal ordinate is represented frequency, and unit is hertz; Ordinate is the normalization spectral power, and unit is every hertz of watt; Method with infinitesimal analysis becomes the n equal portions to incident light spectrum according to frequency partition, and each part got its centre frequency, and the frequency range of each part is Δ f, f _iBe the centre frequency of any one little rectangle wherein, its amplitude is P (f _j);

Fig. 4 is the spectrum recovering figure that adopts the utility model spectrometer to obtain; Among the figure, last horizontal ordinate is represented wavelength, and unit is nanometer; Following horizontal ordinate is represented frequency, and unit is Terahertz; Ordinate is the normalization spectral power, and unit is every hertz of watt; Solid line among the figure is represented incident light spectrum, and the dotted line among the figure represents to restore spectrum.

Embodiment

Below in conjunction with accompanying drawing the technical solution of the utility model is elaborated:

Thinking of the present utility model is at ledge structure used in the prior art or opening diffracting structure light-splitting device complex manufacturing technology, realizes the high problem of cost, utilization has the clear coat of bubble as the light-splitting device of the utility model spectrometer, owing to the manufacturing process of the clear coat that has transparent bubble is simple, and then can significantly reduce manufacturing cost keeping existing array structure micro spectrometer should have under the prerequisite of performance.

Spectrometer architecture of the present utility model comprises the optical alignment device, light-splitting device, the array detection chip 3 that set gradually along the light path incident direction as shown in Figure 1, and the data collection and analysis system that is connected with described array detection chip 3.As shown in the figure, light-splitting device of the present utility model comprises transparent substrates 2, and one of them surface of transparent substrates 2 (also can be two surfaces) be attached with the clear coat 1 that one deck (or multilayer) has bubble.Fig. 2 has shown the vertical view of clear coat 1, as shown in Figure 2, includes the transparent bubble 6 of a packet size or shape uneven distribution in the clear coat 1.Optical alignment device in the present embodiment comprises two confocal lens 4, and the aperture 5 that is arranged at the common focus place of two lens 4.Described array detection chip 3 can adopt CCD or CMOS as detecting element, and it reads the data collection and analysis system (not shown) that circuit, A/D change-over circuit, acquisition control circuit and computing machine constitute with spectral signal and links to each other.

Incident light by light-splitting device, is radiated on each pixel elements of array detection chip 3 behind optical alignment device collimation at last.When through the photometry for the treatment of behind the collimation diffraction and interference in various degree taking place when passing each bubble that differs in size in the bubble coating.Specific as follows:

1, the light of different wave length is mapped to the same area of same bubble, and the angle of diffraction of the different wave length diffraction light of outgoing has nothing in common with each other, and can form certain diffraction intensity and distribute.

2, the light of same wavelength can form after the outgoing and interfere by the different parts of same bubble.Because the bubble size shape is different, the phase differential between the emergent light has nothing in common with each other, and interference light intensity is also different.

3, behind the different parts of the light of same wavelength by different bubbles diffraction taking place, also can interfere between the identical diffraction light in the direction of propagation.

Owing to interfere and diffraction effect, after incident light passed through bubble coating, its below will form certain interference and diffraction light distributes, and different pixel elements will collect the luminous power that differs in size in the final detection array chip.According to the number of used pixel elements, the frequency range that pixel elements can be surveyed evenly to be divided, the normalized power of the centre frequency of each part in incident light is as unknown number; The value that the pixel elements at the diverse location place of array detection chip is detected is as augmented matrix; Record each pixel elements at detection array chip diverse location place in advance to the detectivity of each frequency component, and with this detectivity as matrix of coefficients; Find the solution matrix equation by regularization method, and the gained result is carried out the spectrum that linear fit, spectral calibration just can obtain treating photometry.

The method for making of light-splitting device described in the utility model can have multiple, enumerates two kinds below:

First method is: inert gases such as helium, neon, argon gas, krypton gas or xenon are injected in polymethylmethacrylate (PMMA) and derivant or polystyrene (PS) or the polycarbonate polymer melts such as (PC) continuously, and by ultrasound wave the inert gas bubble is carried out refinement, treat in the polymer melt air bubble content and distribution level off to stable after, it is coated on the transparent substrates surface, cooling makes polymer melt be solidified as polymer coating then, like this, will in polymer coating, produce skewness, bubble not of uniform size.

Second method is: at a certain temperature, with polymer dissolution such as PMMA, PS or PC (for example tetrahydrofuran, acetone, toluene etc.) in organic solvent, obtain the solution of polymkeric substance such as PMMA, PS or PC, after the stirring it is spin-coated on the transparent substrates, and slowly be cooled to room temperature, in the process of cooling, the volatilization of solvent causes producing different pore in formed polymer coating.

The principle of spectrum recovering of the present utility model is: incident light shines on the clear coat after collimating, owing to include bubble not of uniform size, skewness in the clear coat, incident light sees through bubble, and in various degree interference and diffraction will take place, different variations has taken place in the phase differential that sees through each wavelength light of different bubbles, make the bubble below form certain Distribution of Coherent, the pixel elements of final detection array chip CCD will collect a series of luminous powers that differ in size.The gained data are formed a system of linear equations, wherein different pixels unit to the detectivity of different centre wavelength light as matrix of coefficients, and the received corresponding luminous power of each pixel elements is as augmented matrix, find the solution this system of linear equations and just can obtain the normalization spectral power of each centre wavelength correspondence of incident light, then these spectral power values are carried out linear fit and can obtain the spectrum of incident light through spectral radiometric calibration.

The detailed process of spectrum recovering is as follows:

As shown in Figure 3, the frequency range that the detection array chip can be surveyed according to the quantity of detection array chip valid pixel unit evenly is divided into n part, and the centre frequency of each part is f ₁, f ₂... f _n, frequency range is Δ f, the luminous power of every band frequency is approximately the area of each little rectangle among the figure in the incident light.The incident light spectrum that need survey can carry out linear fit by the corresponding luminous power amplitude of each frequency among the figure and obtain, so the target of spectrum recovering is converted into the height P (f that asks each little rectangle among the figure ₁), P. (f ₂) ... P (f _n).

According to the infinitesimal analysis principle, the general power of incident light can be approximated to be among the figure summation of each little rectangular area, the i.e. superposition of each frequency component power below the curve.If represent with mathematical formulae, can be expressed as:

P ₀=P(f ₁)Δf+P.(f ₂)Δf+…+P(f _n)Δf

After incident light is through the microstructure array, detected by one of them pixel elements, the power that this pixel elements receives can be by self direct detection.And on the other hand, the power that the CCD pixel elements detects also can calculate by incident light spectrum.Because the power of each frequency, namely the area of each little rectangle among the figure is detected Shi Douyou by certain pixel elements and to a certain degree reduces.And because interference or the diffraction of different bubbles, make that the light of each frequency component of incident light is different in the ratio that each CCD pixel elements reduces.These reduce ratio is a fixed value after device is carried out, and can calculate through being mapped to the detectivity of being surveyed by this pixel elements on some CCD pixel elements behind the bubble coating by the light of measuring each frequency in the incident beam in advance.Therefore just can obtain an equation, the left side of equation is the power measurement values of CCD pixel elements, the right of system of equations resulting calculated value of addition again after to be the watt level of each frequency in the incident light and CCD pixel elements to the detectivity of each frequency of incident light multiply each other respectively.Suppose to be surveyed by i pixel elements behind the incident light process bubble coating, the big I of the luminous power that obtains on this pixel elements is expressed as:

P _i=C _i1P(f ₁)Δf+C _i2P.(f ₂)Δf+…+C _inP(f _n)Δf

Here, C _I1, C _I2... C _InBeing respectively frequency is f ₁, f ₂... f _nThe detectivity of light through being surveyed by i pixel elements behind the bubble coating.Therefore, n the pixel elements of detection array chip CCD just can record a series of power, and these power can be expressed as system of linear equations:

P ₁=C ₁₁P(f ₁)Δf+C ₁₂P.(f ₂)Δf+…+C _1nP(f _n)Δf,

P ₂=C ₂₁P(f ₁)Δf+C ₂₂P.(f ₂)Δf+…+C _2nP(f _n)Δf,

…

P _n=C _n1P(f ₁)Δf+C _n2P.(f ₂)Δf+…+C _nnP(f _n)Δf,

C wherein _Ij(i=1,2 ... n) (j=1,2 ... n) be that frequency is f _jThe detection coefficient surveyed by i pixel elements of light, namely centre frequency is f _jThe power that detected by i pixel elements of light and the ratio that incides this frequencies of light power before the bubble coating.Record when in advance and respectively to survey coefficient, just can express the measured luminous power of each pixel elements of detection array chip CCD with above-mentioned system of linear equations.If represent with matrix form, establishes transmission coefficient and form matrix of coefficients C, and each detection array chip pixel unit records data composition augmented matrix y, is write as following form respectively:

Then above-mentioned system of linear equations can be expressed as with matrix form:

Cx=y

Here,

$x=\left(\begin{array}{c}P\left(f_1\right)\·\mathrm{\Δf}\\ P\left(f_2\right)\·\mathrm{\Δf}\\ \·\\ \·\\ \·\\ P\left(f_n\right)\·\mathrm{\Δf}\end{array}\right).$

Find the solution above-mentioned system of linear equations system of equations and get x, and further calculate:

$\tilde{x}=x/\mathrm{\Δf}=\left(\begin{array}{c}P\left(f_1\right)\\ P\left(f_2\right)\\ \·\\ \·\\ \·\\ P\left(f_n\right)\end{array}\right).$

Therefore, just can be in the hope of the corresponding power P (f of each frequency component in the incident light spectrum _i) size, with P (f ₁), P.f ₂) ... P (f _n) carry out linear fit, just obtained incident light spectrum.

In solving equation group process, the power that each pixel elements of detection array chip CCD collects and each frequencies of light all are measured values to the transmissivity of each microinterferometer, owing to reasons such as measuring error, this system of equations is real to be the ill-condition equation group, it is more to add in the system of equations quantity of equation, be difficult to find the solution with commonsense method, and that the method that adopts the Tikhonov regularization is found the solution this system of linear equations effect is better, get final product after this system of equations is found the solution the normalization spectral power of each frequency correspondence of incident light, carry out the recovery spectrum that spectral radiometric calibration has just obtained incident light at last.

Fig. 4 adopts the utility model to carry out the simulation result of spectrum recovering, and this figure has compared incident light spectrum (solid line) and restored spectrum (dotted line), goes up horizontal ordinate among the figure and represents wavelength, and unit is nanometer; Following horizontal ordinate is represented frequency, and unit is hertz; Ordinate is the normalization spectral power, and unit is every hertz of watt.The quantity of used pixel elements is 25, the survey frequency scope be 400THz to 800THz, as seen from the figure, restore spectrum and coincide better with the incident light spectroscopic data.

Claims (4)

1. spectrometer, comprise the optical alignment device, light-splitting device, the array detection chip that set gradually along the light path incident direction, and the data collection and analysis system that is connected with described array detection chip, it is characterized in that, described light-splitting device comprises transparent substrates, set is gone up at least one surface of described transparent substrates one deck clear coat at least, includes the bubble of a packet size or shape uneven distribution in the described clear coat.

2. spectrometer according to claim 1 is characterized in that described clear coat is polymkeric substance.

3. as spectrometer as described in the claim 2, it is characterized in that described polymkeric substance is polymethylmethacrylate, polymethylmethacrylate derivant, polystyrene or polycarbonate.

4. spectrometer according to claim 1 is characterized in that described optical alignment device comprises two confocal lens, and the aperture that is arranged at the common focus place of described two lens.

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