CN-116973351-B - Raman spectrometer chip based on Mach-Zehnder interference

CN116973351BCN 116973351 BCN116973351 BCN 116973351BCN-116973351-B

Abstract

The invention provides a Raman spectrometer chip based on Mach-Zehnder interference, which realizes 360-degree turning of an input light direction and realizes interference through optical paths with different lengths by using Mach-Zehnder interference principle and combining two reflections of first to fourth directional couplers and an arrangement mode thereof, and can effectively reduce the chip volume and the cost without using 180-degree bending waveguides; in addition, the composite parabolic condenser lens is arranged on the side end surface of the spectrometer chip based on Mach-Zehnder interference, the end surface coupling is not polarization-selective, the size of a light spot is matched with the size of a coupling-in structure through the condensing effect of a lens, light is fully focused on the side surface of the chip and enters the spectrometer chip, and light spots fully enter the chip through the lens, so that the coupling efficiency of the light is greatly improved.

Inventors

ZHANG ZHEWEI
CHEN CHANG

Assignees

上海近观科技有限责任公司

Dates

Publication Date: 20260508
Application Date: 20220424

Claims (10)

1. A Raman spectrometer chip based on Mach-Zehnder interference is characterized by comprising a package body, a composite parabolic condenser and a lens, wherein the package body is packaged together with an image sensor chip on the basis of the Mach-Zehnder interference; the spectrometer chip based on Mach-Zehnder interference comprises a plurality of spectrometer units which are arranged side by side up and down and are based on Mach-Zehnder interference; Each spectrometer unit based on Mach-Zehnder interference comprises an optical coupling structure, a first 50/50 beam splitter, a first directional coupler and a second directional coupler which are connected with two output ends of the first 50/50 beam splitter in sequence, a third directional coupler and a fourth directional coupler which are connected with the output ends of the first directional coupler and the second directional coupler respectively, and a second 50/50 beam splitter which is connected with the output ends of the third directional coupler and the fourth directional coupler; the optical path difference of each spectrometer unit based on Mach-Zehnder interference is sequentially increased or decreased along the arrangement direction; the first directional coupler, the second directional coupler, the third directional coupler and the fourth directional coupler are arranged up and down side by side, the first directional coupler and the third directional coupler are arranged on the upper side of one output end of the first 50/50 beam splitter and are staggered left and right, and the second directional coupler and the fourth directional coupler are arranged on the lower side of the other output end of the first 50/50 beam splitter and are staggered left and right; the composite parabolic condenser is arranged on the end face of the spectrometer chip based on Mach-Zehnder interference, and input light is coupled into the light coupling structure through focusing of the lens; the image sensor chip is arranged behind the output end of the second 50/50 beam splitter so as to receive interference light output by the second 50/50 beam splitter.
2. A Mach-Zehnder interference based Raman spectrometer chip according to claim 1, wherein the optical path difference of each Mach-Zehnder interference based spectrometer unit is equal in difference in the arrangement direction or is equal in difference in the arrangement direction.
3. The Mach-Zehnder interference based Raman spectrometer chip according to claim 1, wherein the first 50/50 beam splitter is a1×2MMI optical beam splitter or a 50/50 coupler.
4. The Mach-Zehnder interference based Raman spectrometer chip according to claim 1, wherein the first directional coupler, the second directional coupler, the third directional coupler and the fourth directional coupler are 50/50 directional couplers.
5. The Mach-Zehnder interference based Raman spectrometer chip according to claim 1 or 4, wherein the first directional coupler, the second directional coupler, the third directional coupler and the fourth directional coupler are four-port elements, and comprise an input end, an output end and two reflecting ends provided with reflecting mirrors, and a coupling waveguide area is arranged between the four ports.
6. The Mach-Zehnder interference based Raman spectrometer chip according to claim 1, wherein an optical filter is further arranged behind the composite parabolic condenser to filter excitation light introduced in the front-end system.
7. The Mach-Zehnder interference based Raman spectrometer chip as recited in claim 1, wherein the optical incoupling structure comprises an incoupling waveguide and a wedge waveguide connected in sequence to realize chip incoupling of input light.
8. The Mach-Zehnder interference based Raman spectrometer chip according to claim 1, wherein the lens is a cylindrical lens.
9. The Mach-Zehnder interference based Raman spectrometer chip according to claim 1, wherein the image sensor chip is one of a CCD chip, a CMOS image sensor chip, a PD array, a SPAD array, a PMT array and a SiPM array, and the image sensor chip is a one-dimensional array.
10. The Mach-Zehnder interference based Raman spectrometer chip according to claim 1, wherein the Mach-Zehnder interference based spectrometer chip is formed on a silicon substrate or on a silicon nitride substrate or on a lithium niobate substrate or on a glass substrate.

Description

Raman spectrometer chip based on Mach-Zehnder interference Technical Field The invention relates to the field of Raman spectrum detection, in particular to a Raman spectrometer chip based on Mach-Zehnder interference. Background Raman scattering is inelastic scattering, in which photons are interacted due to vibration of molecules of a substance when the light is irradiated on the substance, and the photons are scattered at different frequencies from the excitation light, so that different molecules and even different chemical bonds have different raman peak positions, and the raman spectrum has the characteristics of nondestructive, noninvasive, no need of sample processing, rich information, high analysis efficiency and the like, and is widely applied to the fields of biology, chemistry, medical treatment, food safety, aerospace, environmental protection and the like. However, the luminous intensity of raman scattering itself is very weak, the intensity of conventional raman signal is only 10 -6～10-12 of the incident light intensity, and it is very difficult to detect raman signal, so how to make the apparatus receive raman signal as much as possible is always a design focus of raman spectrum detection apparatus. The design of the existing mature Raman spectrometer is limited by the maximum light flux allowed by a device structure, and is difficult to receive enough signals on the premise of keeping high spectral resolution, so that higher requirements on the aspects of data processing and fitting algorithms are provided for subsequent Raman signal extraction. The chip type Raman spectrometer has a small volume, can realize miniaturization and portability of the spectrometer, and can even realize wearable equipment, and is used for disease and health management and monitoring. However, the chip type Raman spectrometer has few products, almost no products, insufficient volume, low light receiving efficiency, low signal to noise ratio and the like. Disclosure of Invention In view of the above drawbacks of the prior art, an object of the present invention is to provide a raman spectrometer chip based on mach-zehnder interference, which is used for solving the problems of large volume, low light receiving efficiency, low signal-to-noise ratio, and the like of the raman spectrometer chip in the prior art. To achieve the above and other related objects, the present invention provides a raman spectrometer chip based on mach-zehnder interference, which comprises a package body in which the spectrometer chip based on mach-zehnder interference and an image sensor chip are packaged together, and a compound parabolic condenser and a lens mechanically connected with the package body; the spectrometer chip based on Mach-Zehnder interference comprises a plurality of spectrometer units which are arranged side by side up and down and are based on Mach-Zehnder interference; Each spectrometer unit based on Mach-Zehnder interference comprises an optical coupling structure, a first 50/50 beam splitter, a first directional coupler and a second directional coupler which are connected with two output ends of the first 50/50 beam splitter in sequence, a third directional coupler and a fourth directional coupler which are connected with the output ends of the first directional coupler and the second directional coupler respectively, and a second 50/50 beam splitter which is connected with the output ends of the third directional coupler and the fourth directional coupler; the optical path difference of each spectrometer unit based on Mach-Zehnder interference is sequentially increased or decreased along the arrangement direction; the first directional coupler, the second directional coupler, the third directional coupler and the fourth directional coupler are arranged up and down side by side, the first directional coupler and the third directional coupler are arranged on the upper side of one output end of the first 50/50 beam splitter and are staggered left and right, and the second directional coupler and the fourth directional coupler are arranged on the lower side of the other output end of the first 50/50 beam splitter and are staggered left and right; the composite parabolic condenser is arranged on the end face of the spectrometer chip based on Mach-Zehnder interference, and input light is coupled into the light coupling structure through focusing of the lens; the image sensor chip is arranged behind the output end of the second 50/50 beam splitter so as to receive interference light output by the second 50/50 beam splitter. Optionally, the optical path difference of each spectrometer unit based on Mach-Zehnder interference increases or decreases along the arrangement direction of the spectrometer unit. Optionally, the first 50/50 splitter is a 1×2MMI optical splitter or a 50/50 coupler. Optionally, the first directional coupler, the second directional coupler, the third directional coupler, and the fourth directional coup