TW201512635A - Scanning grating spectrometer - Google Patents

Abstract

A scanning grating spectrometer configured to transform a light to be measured into a spectrum. The scanning grating spectrometer includes a scanning grating, at least one reference light source, at least two light receiving modules, and a processing unit. The reference light source is configured to provide a collimated reference light. The light receiving modules receives the reference light modulated by the scanning grating so as to produce reference signals. The processing unit captures the reference signals and calibrates the spectrum according to the time differences between the reference signals respectively received by the light receiving modules.

Description

Scanning grating spectrometer

The present disclosure is directed to a spectrometer, and more particularly to a scanning grating spectrometer.

In recent years, due to the vigorous development of various fields such as electronics, biochemistry, medicine, and optoelectronics, the demand for analysis of physical and chemical properties of various materials has increased. The spectrometer is a kind of physicochemical analysis instrument, which can be divided into different kinds of spectrometers according to its working wavelength range, such as ultraviolet-visible spectrometer, near-infrared spectrometer and infrared spectrometer. UV-visible spectrometers are commonly used for color measurement, water quality analysis, and biochemical tests. Forbidden infrared spectrometers can be used for process monitoring in the food processing industry and the pharmaceutical industry. Infrared spectrometers are commonly used for gas analysis. Spectral analysis features non-destructive, chemically discriminating, wavelength-variable, high sensitivity and fast analysis.

Conventional spectrometers are generally linear detection elements such as a charged coupled device line array sensor. The wavelength of the spectrum corresponds to the relative position on the linear detection element, in other words, a wavelength and light. A spatial function that detects the position of a component.

However, linear sensing components are often expensive, especially in spectrometers. The charge-coupled component detector used does not easily increase the signal-to-noise ratio, so a cooling system is needed to reduce noise.

The scanning spectrometer is a scanning grating with a single-point photodetecting element. By scanning the scanning grating, the single-point photodetecting component can obtain the signal of the individual optical wavelengths at different times to describe the spectrum, in other words, It is a function of the time of the wavelength and the raster scan speed. Scanning spectrometers are less expensive and can have higher signal-to-noise ratios because they do not require the use of expensive linear array charge-coupled component detectors and cooling systems.

However, the scanning spectrometer has the following disadvantages: in general, the rotational frequency of the scanning grating is regarded as a fixed constant, and once the scanning frequency is unstable due to the reason (the frequency of the raster scanning rotation changes, the angular range of the scanning changes, etc.), This will result in an incorrect spectrum.

The scanning grating spectrometer of an embodiment of the present disclosure is adapted to convert a light to be measured into a spectrogram. The scanning grating spectrometer comprises a scanning grating, at least one reference light source, at least two light receiving modules and a processing unit. The reference source is adapted to provide collimated reference light to the scanning grating. The light receiving module receives the reference light modulated by the scanning grating to generate a plurality of reference signals respectively. The processing unit captures the reference signals generated by the light receiving modules, and corrects the spectrum according to the time difference between the reference signals received by the light receiving modules.

The scanning grating spectrometer of an embodiment of the present disclosure is suitable for measuring a light to be measured Converted to a spectrogram, the scanning grating spectrometer comprises a scanning grating, at least two reference light sources, at least one light receiving module and a processing unit. The reference source is adapted to provide a plurality of reference lights that are collimated and have different wavelengths, respectively, to the scanning grating. The light receiving module receives the reference light modulated by the scanning grating to generate a plurality of reference signals. The processing unit captures the reference signals generated by the light receiving module, and corrects the spectrum according to the time difference between the reference signals of the reference lights having different wavelengths received by the light receiving module.

The above described features and advantages of the present invention will be more apparent from the following description.

10‧‧‧Substrate

20‧‧‧Insulation

30‧‧‧矽layer

30', 30" ‧‧‧ crystal pattern layer

40, 50‧‧‧ photoresist pattern layer

100, 200, 300, 400‧‧‧scanning grating spectrometer

110‧‧‧Scan grating

110'‧‧‧Scanned concave grating

112‧‧‧Actuator

114‧‧‧Raster

112a‧‧‧Activity unit

112b‧‧‧Support framework

120, 221, 222‧‧‧ reference light source

130‧‧‧Processing unit

140‧‧‧Mirror group

160‧‧‧Shade housing

A-A’, B-B’‧‧‧ directions

G‧‧‧pattern

H‧‧‧through hole

K, K’, Z1, Z2‧‧‧ areas

M‧‧‧ metal layer

PD, PD1, PD2‧‧‧ optical receiving module

PZ‧‧‧ piezoelectric material layer

RB, RB1, RB2‧‧‧ reference light

RS, RS1, RS2‧‧‧ reference signals

SB‧‧‧Measured light

ST‧‧‧Injection slit

ST', ST'1, ST'2‧‧‧ receiving slit

SU‧‧‧Light detection unit

SP‧‧‧Vibration structure

△t‧‧‧ time difference

1 is a schematic diagram of a scanning grating spectrometer in a first embodiment of the present disclosure.

2A is a schematic view showing the optical path of the scanning grating of the scanning grating spectrometer in the embodiment of FIG. 1 when the rotation is at an angle.

2B is a schematic view showing the optical path of the scanning grating of the scanning grating spectrometer in the embodiment of FIG. 1 when the rotation is at another angle.

2C is a schematic diagram showing signal intensity versus time detected by the scanning grating spectrometer 100 in the first embodiment of the present disclosure.

2D is a graph showing the signal intensity versus time of the light to be detected detected by the scanning grating spectrometer of the present disclosure.

2E depicts a spectrogram converted from the pattern of signal intensity versus time of FIG. 2D.

FIG. 2F illustrates another embodiment of the light receiving modules PD1, PD2 in the embodiment of FIG. 1.

FIG. 3A is a schematic perspective view of a scanning grating in the first embodiment of the present disclosure.

FIG. 3B is a partially enlarged schematic view of the area Z1 of FIG. 3A.

Figure 3C depicts a top view of the scanning grating of Figure 3A.

FIG. 3D is a partially enlarged schematic view of the region Z2 of FIG. 3C.

Figure 3E depicts a side view of the scanning grating of Figure 3A.

4A through 4I illustrate the steps of fabricating the support frame, the grating, and the vibrating structure.

FIG. 5A is a schematic view showing the optical path of the scanning grating of the scanning grating spectrometer in the second embodiment when the rotation is at an angle. FIG.

FIG. 5B is a schematic view showing the optical path of the scanning grating of the scanning grating spectrometer in the embodiment of FIG. 5A when the rotation is at another angle. FIG.

6 is a schematic view showing a scanning grating spectrometer in a third embodiment of the present disclosure.

FIG. 7 is a schematic view showing a scanning grating spectrometer in a fourth embodiment of the present disclosure.

1 is a schematic diagram of a scanning grating spectrometer in a first embodiment of the present disclosure. Referring to FIG. 1, in the present embodiment, the scanning grating spectrometer 100 is adapted to convert a light to be measured SB into a spectrogram, a scanning grating. The spectrometer 100 includes a scanning grating 110, at least one reference light source 120, at least two light receiving modules (two in this embodiment as an example) PD1, PD2, and a processing unit 130. The reference source 120 is adapted to provide collimated reference light RB to the scanning grating 110. The light receiving modules PD1 and PD2 receive the reference light RB modulated by the scanning grating 110 to generate a reference signal RS. The processing unit 130 captures the reference signal RS generated by the light receiving modules PD1 and PD2, and corrects the spectrum according to the time difference between the reference signals RS1 and RS2 received by the light receiving modules PD1 and PD2. The details of the correction will be detailed later.

In this embodiment, the scanning grating spectrometer 100 further includes a mirror group 140, and the scanning grating 110 is a reflective grating. For example, the mirror group 140 in this embodiment may be a concave mirror having a light collecting capability, but the disclosure is not limited thereto. The reference light RB and the light to be measured SB may enter the scanning grating spectrometer 100 from the incident slit ST, be collimated by the mirror group 140 and reflected to face the scanning grating 110, and then reflected by the scanning grating 110 to the mirror. After the group 140 is transmitted to the side where the light receiving modules PD1, PD2 are located, it can be detected.

In addition, in order to reduce reflected light or scattered light other than expected, a light absorbing material may be coated on the inner surface of the light shielding case 160 of the scanning grating spectrometer 100, and the material of the light absorbing material may be, for example, chromium oxynitride (CrNO). The incident slit ST can also be formed on a chromium oxynitride film.

The arrangement position and the light transmission path of the components shown in FIG. 1 are exemplified. The disclosure is not limited thereto, and may be different in other embodiments.

Hereinafter, for ease of understanding, the optical path of the light to be measured SB will be omitted in FIGS. 2A and 2B.

2A is a schematic view showing the optical path of the scanning grating of the scanning grating spectrometer in the embodiment of FIG. 1 when the rotation is at an angle. 2B is a schematic view showing the optical path of the scanning grating of the scanning grating spectrometer in the embodiment of FIG. 1 when the rotation is at another angle. Referring first to FIG. 1 and FIG. 2A, in the present embodiment, the scanning grating 110 performs a reciprocating rotational scan (eg, reciprocating in the A-A' direction), and the reference light RB is reciprocally scanned (eg, as B-B). The 'direction reciprocating scan' is received by the light receiving module PD1 or the light receiving module PD2 at different points in time.

With continued reference to FIG. 2A, reference light source 120 has, for example, a laser source, and reference source RB is, for example, light having a single wavelength peak provided by a laser source. In FIG. 2A, the scanning grating 110 is rotated to an angle in the A-A' direction, and the reference light RB passes through the incident slit ST to form a point source and is transmitted toward the mirror group 140, which is modulated by the scanning grating 110. Received by the light receiving module PD1. At this time, the optical receiving module PD1 converts the received signal of the reference light RB into the reference signal RS1 and transmits it to the processing unit 130. The processing unit 130 records the time point when the reference light RB is received and the intensity of the reference light RB.

Next, referring to FIG. 2B, in FIG. 2B, the scanning grating 110 is rotated in the A'-A direction to another angle, and the reference light RB is modulated by the scanning grating 110 to be light. The receiving module PD2 receives. At this time, the optical receiving module PD2 converts the received signal of the reference light RB into the reference signal RS2 and transmits it to the processing unit 130. The processing unit 130 records the time point when the reference light RB is received and the intensity of the reference light RB.

Since the scanning grating 110 performs the rotational scanning reciprocally, the reference light RB is also reciprocally rotated and received by the light receiving modules PD1, PD2 at different points in time.

2C is a schematic diagram showing signal intensity versus time detected by the scanning grating spectrometer 100 in the first embodiment of the present disclosure. Referring to FIG. 2A to FIG. 2C, in FIG. 2C, the solid line curve represents the reference light RB. The change of the signal received by the light receiving module PD1 with time, the broken line curve represents the change of the signal received by the reference light RB by the light receiving module PD2 with time, since the reference light RB is reciprocally rotated and received by the light at different time points The modules PD1, PD2 are received, so that in Figure 2C, the peaks of the solid curve and the dashed curve are deduced with time and the interlaced pattern is generated. The time difference Δt between the solid line curve in FIG. 2C and the peak value of the broken line curve indicates that the reference light RB is received by the light receiving module PD1, and then scanned by the scanning grating 110 to the light receiving mode. The time required between group PD2 reception.

On the other hand, in the present embodiment, after the reference light RB is received by the light receiving module PD1, the scanning wavelength range between the receiving of the scanning grating 110 and the receiving by the optical receiving module PD2 (related to the light) If the distance between the receiving module PD1 and the light receiving module PD2 is the wavelength range Δλ, the actual scanning speed of the current scanning grating Δλ can be calculated according to the ratio of the wavelength range Δλ and the time difference Δt. (t), ie: △λ(t)=△λ/Δt

Moreover, since the wavelength of the reference light RB is known and can be set according to requirements, after the actual scanning scanning speed Δλ(t) of the current scanning grating is calculated, the entire wavelength range Δλ can be performed by extrapolation. Perform spectral localization, ie: λ _unknown = Δλ(t) × t' + λ _ref where λ _unknown represents the wavelength of the light to be measured, λ _ref represents the wavelength of the reference light, and t′ represents the light receiving mode The time difference between the light to be measured and the reference light received by the group.

Thereby, the above-mentioned operation is performed by the light detecting modules PD1, PD2 and the scanning grating 110, and the actual scanning scanning speed Δλ(t) of the current scanning grating can be accurately measured, so the signal intensity is time-dependent. The graphics can be accurately located so that a spectral map of the precise wavelength can be obtained based on the graphical conversion of this signal strength versus time.

2D is a graph showing the signal intensity versus time of the light to be detected detected by the scanning grating spectrometer of the present disclosure, and FIG. 2E is a spectrum diagram showing the pattern of the signal intensity versus time of FIG. 2D.

Wherein, since the scanning grating 110 reciprocally rotates and scans, two characteristic peaks appearing in turn according to time in FIG. 2D can be obtained, and when converted into the spectrum diagram of FIG. 2E, the data can be sampled from the time interval in FIG. 2D. The signal data in the S-S', according to the wavelength value of the reference light RB and through the extrapolation method as described above, can obtain the spectrum of the light to be measured SB as shown in FIG. 2E.

On the other hand, the scanning grating spectrometer 100 of the present disclosure can detect the actual scanning grating through two (or more) light detecting modules PD1 and PD2. The rotational scanning speed of 110, therefore, even if the rotational scanning speed of the scanning grating 110 is doubled for some reason, it can be corrected to the correct spectral image. In other words, the scanning grating spectrometer 100 of the present disclosure can correctly reflect the characteristic wavelength peak of the light to be measured SB even under different scanning conditions, and at the same time, can achieve a good resolution (less than 5 nm) at a low cost. For example, through the scanning grating spectrometer 100 of the present disclosure, the resolution of the commercial Raman spectrum (less than 0.3 nm) can be achieved by controlling the resonant frequency of the scanning grating 110.

Further, the scanning grating spectrometer 100 of the present disclosure can selectively correct the spectrogram when scanning the light to be measured SB as needed. Thus, even if the scanning grating 110 changes the rotational scanning speed and angle for some reason during operation, the scanning grating spectrometer 100 can accurately obtain the correct spectral image.

In addition, as shown in FIG. 1, in this embodiment, each of the light receiving modules (PD1, PD2) may include a receiving slit ST' and a light detecting unit SU, and the reference light RB passes through the receiving slit ST. 'Received by the light detecting unit SU. Thus, the spectral resolution of the scanning grating spectrometer 100 can be increased by adjusting the slit size of the receiving slit ST'.

FIG. 2F illustrates another embodiment of the light receiving modules PD1 and PD2 in the embodiment of FIG. 1. Referring to FIG. 1 and FIG. 2F, in FIG. 2F, the light receiving modules PD1 and PD2 are configured by a light detecting unit. SU and at least two receiving slits ST'1, ST'2 are formed, and the reference light RB is received by the photo detecting unit SU through different receiving slits at different time points. In other words, the photodetection module PD1 in FIG. 1 can be obtained from FIG. 2F. The receiving slit ST'1 is implemented by the light detecting unit SU, and the light detecting module PD2 of FIG. 1 can be implemented by the receiving slit ST'2 of FIG. 2F in combination with the light detecting unit SU. In this way, the number of light detecting units SU used can be further reduced, and the cost and volume can be reduced.

In detail, referring again to FIG. 1, in the present embodiment, the scanning grating 110 includes an actuator 112 and a grating 114, and the actuator 112 drives the grating 114 to perform a reciprocating rotational scanning. The actuator 112 is composed of, for example, an integrated circuit and a microelectromechanical system (MEMS), and the disclosure is not limited thereto.

3A is a perspective view showing a scanning grating in the first embodiment of the present disclosure, FIG. 3B is a partially enlarged schematic view of the region Z1 in FIG. 3A, and FIG. 3C is a top view of the scanning grating of FIG. 3A. 3D is a partially enlarged schematic view of the region Z2 of FIG. 3C, and FIG. 3E is a side view of the scanning grating of FIG. 3A. Referring first to FIG. 1 and FIG. 3A, in the present embodiment, the actuator 112 includes The alignment unit 112a and a support frame 112b are disposed in the through hole H in the support frame 112b, and the grating 114 is connected to the support frame 112b through the vibration structure SP (as shown in FIG. 3B).

Wherein, when the actuation unit 112a applies a force to the grating 114 to change the inclination angle of the grating 114 with respect to the support frame 112b, the vibration structure SP is deformed. Thereby, the actuation unit 112a can be driven periodically such that the grating 114 produces periodic reciprocating vibrations for scanning. In the present embodiment, the grating 114 is driven to produce an angle of inclination of up to 9-15 degrees and a vibration frequency of up to 500-1 kHz.

For example, referring to FIG. 3A to FIG. 3C , in the embodiment, the actuation unit 112 a is, for example, a metal layer M including a piezoelectric material layer PZ and sandwiched between the piezoelectric material layers PZ. The piezoelectric material layer PZ may be in contact with the grating 114. The metal layer M is, for example, a metal having good conductivity (copper, gold, silver, etc.), and the control voltage may be transmitted to the piezoelectric material layer PZ through the metal layer M to change the piezoelectric material. The state of the layer PZ, thereby pushing the grating 114, performs the above-described reciprocating rotational scanning. The shape of the member such as the vibrating structure SP in FIG. 3A to FIG. 3E is only for illustrative purposes, and the disclosure is not limited thereto.

In more detail, in the present embodiment, the support frame 112, the grating 114, and the vibrating structure SP in the scanning grating 110 of FIG. 3A may be a structure obtained by etching the same silicon wafer, thereby having good precision. . The fabrication steps of etching the germanium wafer to form the support frame 112, the grating 114, and the vibrating structure SP in this embodiment will be described in detail below.

4A to 4I illustrate the steps of fabricating the support frame, the grating, and the vibrating structure. Referring to FIG. 4A to FIG. 4I, in the embodiment, a silicon-on-insulator (SOI) wafer is used. The structure of the substrate 10, the insulating layer 20, and the twin layer 30 is illustrated in FIG. 4A. First, a photoresist pattern layer 40 (as shown in FIG. 4B) is applied on the side of the twin layer 30 away from the insulating layer 20, wherein the pattern of the photoresist pattern layer 40 is related to the grating pattern to be fabricated. Next, the structure illustrated in FIG. 4B is subjected to an etching means such as exposure, plasma or chemical to form a twinned pattern layer 30' corresponding to the photoresist pattern layer 40 (FIG. 4C), and then the photoresist is removed. Pattern layer 40 (Fig. 4D). Wherein, the pattern g on the twin pattern layer 30' is slightly rounded after being etched. The type is as shown in FIG. 4D, but the disclosure is not limited thereto.

Next, referring to FIG. 4E, a photoresist pattern layer 50 is formed on the twin pattern layer 30', wherein the region K around the region K' of the photoresist pattern layer 50 is a region where the vibration structure SP is to be formed, and the light is The area K' covered by the resist pattern layer 50 is the area where the grating 114 is to be formed (Fig. 4E). After the structure of FIG. 4E is subjected to an etching means such as exposure, plasma or chemical, the twin pattern layer 30' forms a twinned pattern layer 30 in the region K. The vibration structure SP and the through hole H as shown in FIG. 3A. Then, the photoresist pattern layer 50 is removed (as shown in Fig. 4G).

Next, the twin pattern layer 30" is separated from the insulating layer 20 by a structure such as hydrofluoric acid vapor (Vapor HF, VHF) or the like in the structure of FIG. 4G (as shown in FIG. 4H), and may be provided in the twin pattern layer 30". One side of the pattern g was sputtered with aluminum and subjected to aluminum oxide (Al ₂ O ₃ ) atomic layer deposition (ALD) (Fig. 4I). However, the above-described fabrication steps and materials used are merely illustrative, and the disclosure is not limited thereto.

FIG. 5A is a schematic diagram showing the optical path of the scanning grating of the scanning grating spectrometer in the second embodiment when the rotation is at an angle, and FIG. 5B is a scanning diagram of the scanning grating spectrometer in the embodiment of FIG. 5A. Schematic diagram of the optical path of the grating when it is rotated at another angle. Referring to FIG. 1 , FIG. 2A , FIG. 2B , FIG. 5A and FIG. 5B , in the present embodiment, the same reference numerals are used for the same or the same functions as those of the first embodiment, and the scanning grating spectrometer 200 includes: a scanning type The grating 110, at least two reference light sources 221, 222, at least one light receiving module PD, and a processing unit 130. In this embodiment, the number of the light receiving modules PD is, for example, one, and the number of reference light sources The amount is, for example, two (i.e., reference light sources 221, 222). The reference light sources 221, 222 are adapted to provide reference light RB1, RB2 that are collimated and have different wavelengths, respectively, to the scanning grating. The light receiving module receives the reference light RB1, RB2 modulated by the scanning grating 114 to generate reference signals RS1, RS2. The processing unit 130 captures the reference signals RS1 and RS2 generated by the optical receiving module PD, and according to the reference signals RS1 and RS2 received by the optical receiving module PD corresponding to the reference lights RB1 and RB2 having different wavelengths. The time difference between the corrected spectra. The light receiving module PD in the embodiment may be implemented to include a light detecting unit SU and a receiving slit ST′, and the reference light RB1 and RB2 pass through the receiving slit ST. 'It is received by the photo detecting unit SU, so that the resolution of the spectrogram can also be improved, and will not be described again here.

In detail, the scanning grating 114 performs reciprocating rotational scanning so that different reference lights RB1 and RB2 are respectively received by the light receiving module PD at different time points, and the processing unit 130 generates the light according to the light receiving module PD at different time points. The time difference between the reference signals RS1 and RS2 calculates the rotational scanning speed of the scanning grating 114, and the processing unit 130 corrects the spectral map based on the calculated rotational scanning speed.

Hereinafter, for ease of understanding, the optical path of the light to be measured SB will be omitted in FIGS. 5A and 5B.

For example, referring first to FIG. 5A, the scanning grating 110 is rotated to an angle in the A-A' direction, and the reference lights RB1, RB2 are passed through the entrance slit ST to form a point source and are transmitted toward the mirror group 140. Since the wavelengths of the reference lights RB1 and RB2 are different, only the reference light RB1 is modulated by the scanning grating 110 and received by the light receiving module PD in the state of the scanning scanning angle of the scanning grating 114 of FIG. 2A. this The time receiving module PD converts the received signal of the reference light RB1 into the reference signal RS1 and transmits it to the processing unit 130. The processing unit 130 records the time point when the reference light RB1 is received and the intensity of the reference light RB1.

Next, referring to FIG. 5B, in FIG. 5B, the scanning grating 110 is rotated in the A'-A direction to another angle. At this time, only the reference light RB2 is modulated by the scanning grating 110 and is received by the light receiving module PD. receive. At this time, the optical receiving module PD converts the received signal of the reference light RB2 into the reference signal RS2 and transmits it to the processing unit 130. The processing unit 130 records the time point when the reference light RB2 is received and the intensity of the reference light RB2.

Since the wavelengths of the reference lights RB1 and RB2 are known, in the embodiment, the at least one light receiving module PD can be matched with the at least two reference light sources 221 and 222 in the embodiment. The processing unit 130 calculates the actual rotational scanning speed Δλ(t) of the current scanning grating, thereby performing spectral positioning of the entire wavelength range Δλ by using the extrapolation method as described in the first embodiment to correct the light to be measured. Spectrum of SB.

In addition, the optical path structure of the scanning grating spectrometer of FIG. 1 and FIGS. 5A and 5B may have other embodiments. 6 is a schematic diagram of a scanning grating spectrometer in a third embodiment of the present disclosure, and FIG. 7 is a schematic diagram of a scanning grating spectrometer in a fourth embodiment of the present disclosure. Please refer to FIG. 1 and FIG. The scanning grating spectrometer 300 of FIG. 6 does not use the mirror group 140 in the embodiment of FIG. 1, but uses the incident slit ST and the scanning concave grating 110', wherein the light to be measured SB and the reference light RB are incident through the ST. After the slit, direct shooting with splitting and focusing The scanning concave grating 110' can be such that the scanning grating spectrometer 300 in the third embodiment can also have the same efficiency as the scanning grating spectrometer 100 in the first embodiment.

5A, FIG. 5B and FIG. 7, the scanning grating spectrometer 400 of FIG. 7 also does not use the mirror group 140 in the embodiment of FIG. 5A, but uses the incident slit ST and the scanning concave grating 110'. The reference light SB and the reference light RB1 and the reference light RB2 are directly incident on the scanning concave grating 110' having the splitting and focusing functions after passing through the ST incident slit. As such, the scanning grating spectrometer 400 of the fourth embodiment can also have the same efficacy as the scanning grating spectrometer 200 of the second embodiment.

In summary, through the scanning grating spectrometer disclosed in the present disclosure, the actual scanning speed of the current scanning grating can be accurately measured, so that the signal intensity versus time pattern can be accurately positioned, thereby being able to be based on the signal strength. A graphical representation of the time to obtain a spectral map of the precise wavelength.

The present disclosure has been disclosed in the above embodiments, but it is not intended to limit the disclosure, and any person skilled in the art can make some changes and refinements without departing from the spirit and scope of the disclosure. The scope of protection of this disclosure is subject to the definition of the scope of the appended claims.

100‧‧‧Scan Grating Spectrometer

110‧‧‧Scan grating

112‧‧‧Actuator

114‧‧‧Raster

120‧‧‧Reference light source

130‧‧‧Processing unit

140‧‧‧Mirror group

160‧‧‧Shade housing

A-A’, B-B’‧‧‧ directions

PD1, PD2‧‧‧ light receiving module

RB‧‧‧ reference light

RS, RS1, RS2‧‧‧ reference signals

SB‧‧‧Measured light

ST‧‧‧Injection slit

ST’‧‧‧ Receiving slit

SU‧‧‧Light detection unit

Claims (20)

A scanning grating spectrometer adapted to convert a light to be measured into a spectrogram, the scanning grating spectrometer comprising: a scanning grating; at least one reference light source adapted to provide collimated reference light to the scanning grating; at least two The light receiving module receives the reference light modulated by the scanning grating to generate a plurality of reference signals respectively; and a processing unit that captures the reference signals generated by the light receiving modules, and according to the The time difference between the reference signals received by the light receiving modules respectively corrects the spectrum. The scanning grating spectrometer of claim 1, wherein the scanning grating performs a reciprocating rotational scanning, so that the reference light is received by different optical receiving modules at different time points, and the processing unit is different according to different The time difference between the reference signals generated by the light receiving modules at different time points calculates the rotational scanning speed of the scanning grating, and the processing unit corrects the spectrum according to the calculated rotational scanning speed. The scanning grating spectrometer of claim 2, wherein the processing unit calculates the signal intensity versus time data of the signal intensity received by the light receiving module, and compares the signal intensity according to the wavelength of the reference light. The time data is converted to the spectrum of the signal intensity versus wavelength, wherein the processing unit extrapolates the spectrum. The scanning grating spectrometer of claim 1, wherein the scanning The reticle grating includes an actuator and a grating that drives the grating for reciprocating rotational scanning. The scanning grating spectrometer of claim 4, further comprising a mirror group, wherein the scanning grating is a reflective grating, wherein the reference light and the light to be measured are reflected by the mirror group to the scanning type After the grating is reflected by the scanning grating to the mirror group, it is transmitted toward the side where the light receiving module is located. The scanning grating spectrometer of claim 4, wherein the actuator comprises an actuator unit and a support frame, the grating is located in the through hole in the support frame, and the grating transmits the vibration structure and the support frame The connection, wherein when the actuation unit applies a force to the grating to change the inclination angle of the grating relative to the support frame, the vibration structure is deformed to perform a reciprocating rotational scan. The scanning grating spectrometer of claim 6, wherein the support frame, the grating, and the vibrating structure are structures formed by etching the same crucible wafer. The scanning grating spectrometer of claim 1, further comprising: at least one incident slit disposed between the reference light source and the scanning concave grating. The scanning grating spectrometer of claim 1, wherein the at least two light receiving modules comprise a light detecting unit and at least two receiving slits, and the reference light passes through the different receiving slits at different time points. Received by the light detecting unit. The scanning grating spectrometer of claim 1, wherein each of the light receiving modules comprises a receiving slit and a light detecting unit, wherein the reference light is detected by the light after passing through each of the receiving slits. Unit reception. A scanning grating spectrometer adapted to convert a light to be measured into a spectrogram, the scanning grating spectrometer comprising: a scanning grating; at least two reference light sources adapted to respectively provide collimation and different wavelengths to the scanning grating a plurality of reference light beams; the at least one light receiving module receives the reference light modulated by the scanning grating to generate a plurality of reference signals respectively; and a processing unit that captures the generated by the light receiving module The reference signals are corrected according to a time difference between the reference signals received by the light receiving module and corresponding to the reference lights having different wavelengths. The scanning grating spectrometer of claim 11, wherein the scanning grating performs a reciprocating rotational scanning, so that the reference lights of different wavelengths are respectively received by the optical receiving module at different time points, the processing unit The rotational scanning speed of the scanning grating is calculated according to a time difference between the reference signals generated by the light receiving module at different time points, and the processing unit corrects the spectral image according to the calculated rotational scanning speed. The scanning grating spectrometer of claim 12, wherein the processing unit calculates the signal intensity versus time data of the signal intensity received by the light receiving module, and determines the signal strength according to the wavelengths of the reference lights. Information on time Converted to the spectrum of signal intensity versus wavelength, wherein the processing unit extrapolates the spectrogram. The scanning grating spectrometer of claim 11, wherein the scanning grating comprises an actuator and a grating, the actuator driving the grating for reciprocating rotational scanning. The scanning grating spectrometer of claim 14, further comprising a mirror group, wherein the scanning grating is a reflective grating, wherein the reference light and the light to be measured are reflected by the mirror group to the scanning type After the grating is reflected by the scanning grating to the mirror group, it is transmitted toward the side where the light receiving module is located. The scanning grating spectrometer of claim 14, wherein the actuator comprises an actuating unit and a supporting frame, the grating is located in the through hole in the supporting frame, and the grating transmits the vibrating structure and the supporting frame The connection, wherein when the actuation unit applies a force to the grating to change the inclination angle of the grating relative to the support frame, the vibration structure is deformed to perform a reciprocating rotational scan. The scanning grating spectrometer of claim 16, wherein the support frame, the grating, and the vibrating structure are structures formed by etching the same crucible wafer. The scanning grating spectrometer of claim 11, further comprising: at least one incident slit disposed between the reference light source and the scanning concave grating. The scanning grating spectrometer of claim 11, wherein the The light receiving module includes a light detecting unit and a receiving slit, and the reference light is received by the light detecting unit through the receiving slit. The scanning grating spectrometer of claim 11, wherein the reference source is a laser source that supplies monochromatic wavelength light.