TW201350813A - Diffraction grating devices, spectroscopes, and spectroscopy systems - Google Patents

Abstract

The present invention provides a diffraction grating device, comprising a first surface; a second surface and a third surface, opposite the first surface, wherein said second surface and said third surface are not coplanar, and said third surface is closer to the first surface than said second surface; a side surface located between the first surface and the second surface; and a grating surface located between the first surface and the third surface. The present invention also provides a spectroscope or a spectroscopy system, comprising the diffraction grating device.

Description

Diffraction grating device, spectroscopic device and spectroscopic system

The present invention relates to a reflective diffraction grating device and a beam splitting device and a spectroscopic system including the same.

U.S. Patent No. 5,550,375 discloses an infrared spectrometer ( 100 , see Fig. 1A) of a measurable gas comprising a microstructure having a reflective diffraction grating 110 . The grating structure 210 and the substrate 220 are made of a plastic material and integrally formed by a LIGA process (see FIG. 1B). However, the substrate 220 is a lower waveguide in the system structure, but the LIGA process has the problem of being difficult to demold, which will improve the roughness of the surface of the substrate 220 , thereby affecting the optical signal quality of the overall system.

An optical system comprising a diffraction grating 310 and a substrate 320 (see FIG. 2), the grating comprising: a first upper surface 314 , a second upper surface 316 , a lower surface, and a Side 318 , wherein the side 318 interfaces with the substrate 320 . However, when the optical signal of the system is transmitted in the internal space 330 , the roughness of the second upper surface 316 of the grating will affect the quality of the optical signal; further, when the grating 310 and the substrate 320 are assembled and joined, The second upper surface 316 must be accurately controlled to be level with the upper surface of the substrate 320 , but the above components are very small, and it is difficult to control and adjust the level of the assembly, and if there is a slight difference in assembly, the noise will be seriously increased. , which in turn affects the performance of the overall system.

Therefore, there is still a need for a diffraction grating device having an improved structure to simplify the assembly process and improve the performance of the optical system.

The present invention provides a diffraction grating device comprising: a first surface; a second surface and a third surface opposite to the first surface, wherein the second surface and the third surface are in different planes, and the The third surface is closer to the first surface than the second surface; a side surface is coupled to the second surface and the third surface And a diffraction surface connected between the first surface and the third surface.

In another aspect, the present invention provides a spectroscopic device comprising: a diffraction grating device of the present invention; a first cover; and a second cover, wherein the first cover system is coupled to the first surface, The second cover system is coupled to the third surface, and the diffraction grating device, the first cover and the second cover form an internal space, and the diffraction surface faces the internal space. In the internal space of the spectroscopic device of the present invention, except for the diffractive surface, the upper optical waveguide and the lower optical waveguide are composed of the first cover or the second cover, and no other heterogeneous surface affects optical signal transmission, and via the third The surface and the side surface are joined to the cover body, and the assembly is convenient and the drop is not easily generated.

In still another aspect, the present invention provides a spectroscopic system comprising: an input portion for receiving an optical signal; a spectroscopic device of the present invention; and an output portion.

Detailed descriptions of various specific examples of the invention are given below. Other features of the present invention will be apparent from the following detailed description and claims.

Without further elaboration, it is believed that those of ordinary skill in the art of Therefore, it is to be understood that the following description is for illustrative purposes only and is not intended to limit the disclosure.

All technical and scientific terms used herein have the meaning as commonly understood by one of ordinary skill in the art to which the invention pertains, unless otherwise indicated.

The term "a" as used herein, unless otherwise specified, refers to the quantity of at least one (one or more).

In one aspect, the invention provides a diffraction grating device comprising: a first surface; a second surface and a third surface relative to the first surface, wherein the second surface and the third surface are different a plane, and the third surface is closer to the first surface than the second surface; a side surface connected to (or located between) the second surface and the third surface; and a diffraction surface Connected to (or located between) the first surface and the third surface.

4 is a preferred embodiment of the present invention, the diffraction grating device 410 includes a first surface 414 , a second surface 416 and a third surface 417 opposite the first surface 414 , and a side surface 418 connected to The second surface 416 and the third surface 417 , and the diffraction surface 412 are connected between the first surface 414 and the third surface 417 .

In a preferred embodiment of the invention, the diffraction grating device is a reflective grating.

In a preferred embodiment of the invention, the diffractive surface is a concave surface. According to some embodiments of the invention, the concave surface is spherical or aspherical.

According to a preferred embodiment of the present invention, the first surface and the third surface have a first vertical distance, the second surface and the third surface have a second vertical distance, and the first There is a third vertical distance between the surface and the second surface, wherein the third vertical distance is the sum of the first vertical distance and the second vertical distance.

The material of the diffraction grating device of the present invention may be selected from the group consisting of metal, glass, plastic and semiconductor.

In some embodiments of the invention, the diffractive surface may be plated with a metal film or a dielectric film by electroplating, evaporation, sputtering, vapor deposition or polishing.

In a specific embodiment, the diffraction grating device of the present invention comprises: an upper surface (first surface); a first lower surface (second surface) and a second lower surface (third surface), wherein the first The lower surface and the second lower surface are located on different planes, and the second lower surface is closer to the upper surface; a side surface is connected to (or is located between) the first lower surface and the second lower surface And a diffraction surface connected to (or located between) the upper surface and the second lower surface.

In another embodiment, the diffraction grating device of the present invention comprises: a lower surface (first surface); a first upper surface (second surface) and a second upper surface (third surface), wherein the An upper surface and the second upper surface are located on different planes, and the second upper surface is closer to the lower surface; a side surface is connected to (or is located between) the first upper surface and the second upper surface And a diffractive surface connected to (or located between) the second upper surface and the lower surface.

In another aspect, the present invention provides a spectroscopic device comprising: a diffraction grating device of the present invention; a first cover; and a second cover, wherein the first cover system is coupled to the first surface, The second cover system is coupled to the third surface, and the diffraction grating device, the first cover and the second cover form an internal space, and the diffraction surface faces the internal space.

Therefore, in the internal space of the spectroscopic device of the present invention, except for the diffractive surface, the upper optical waveguide and the lower optical waveguide are composed of the first cover or the second cover, and no other heterogeneous surface affects optical signal transmission, and The third surface is engaged with the cover body, and the assembly is convenient and the drop is not easy to occur, and the performance of the spectroscopic device can be significantly improved.

In some embodiments of the invention, the second cover is further joined to the side.

In a preferred embodiment of the present invention, as shown in FIG. 4, the spectroscopic device 400 includes a diffraction grating device 410 of the present invention, a first cover 420 , and a second cover 430 . The first cover 420 is engaged with the first surface 414 , the second cover 430 is engaged with the third surface 417 and the side 418 , the diffraction grating device 410 , the first cover 420 and the second The cover 430 forms an interior space 440 and the diffractive surface 412 faces the interior space 440 .

In a specific embodiment of the present invention, the spectroscopic device comprises a diffraction grating device comprising: an upper surface, a first lower surface, a second lower surface, and a side surface connected to (or located) a first lower surface and the second lower surface, and a diffraction surface connected between (or located between) the upper surface and the second lower surface; an upper cover (first cover) And a lower cover (second cover), wherein the upper cover is engaged with the upper surface, the lower cover is engaged with the second lower surface and the side, and the diffraction grating device, the upper cover and the lower cover form a An internal space, and the diffraction surface faces the internal space. In this embodiment, the upper cover (first cover) serves as an upper optical waveguide, and the lower cover (second cover) serves as a lower optical waveguide.

According to the present invention, the materials of the first cover and the second cover may be selected from the group consisting of metal, glass, plastic and semiconductor, respectively.

According to the present invention, the first cover body and the second cover body are in contact with the internal space At least one reflective layer may be covered, and the reflective layer may be a metal film or a dielectric film.

In still another aspect, the present invention provides a spectroscopic system comprising: an input portion for receiving an optical signal; a spectroscopic device of the present invention; and an output portion.

In a specific embodiment of the invention, the input portion is a slit. In another embodiment, the input portion is an optical fiber.

In an embodiment of the invention, the output portion is an optical fiber. According to some embodiments of the invention, the output portion includes a photodetector.

As used herein, "photodetector" refers to a detector that converts optical signals into electrical signals using photosensitive elements. In particular, the photodetectors include, but are not limited to, photodiode array detection. , electrical coupling component photodetector, complementary MOS sensor, and photomultiplier detector.

Example 1 : Influence of waveguide surface roughness on optical system in a spectroscopic device

Comparing the prior art, such as the light splitting device 300 of FIG. 2, and the light splitting device 400 of FIG. 3, when the second upper surface 316 and the third surface 417 of the grating are not flat (see the schematic diagrams of FIGS. 4A and 4B, FIG. 4A). For the prior art, FIG. 4B is the invention, and the optical signal is affected when it is transmitted in the internal space of the above-mentioned spectroscopic device. It is assumed that the distance between the upper and lower optical waveguides is 100 μm, and the optical total lumen efficiency (Total Flux) (%) when the optical signal is transmitted to the spectroscopic device is calculated by the optical tracing software. As a result, as shown in FIG. 4C, since the prior art is as shown in the spectroscopic device 300 of FIG. 2, the second upper surface 316 of the grating also serves as a part of the waveguide, when the surface has a coarse structure of different scattering degrees (0% to 100%). The optical overall lumen efficiency of the optical system will be affected. When the degree of scattering is higher, the optical overall lumen efficiency is lower; the grating device of the present invention has no such problem, since only the diffraction surface faces the internal space, the upper and lower optical waveguides are Homogeneous material, no other heterogeneous surface affects the optical signal transmission, so the optical overall lumen efficiency is not affected by the roughness of the other surfaces of the grating.

Example 2 : The influence of optical waveguide spacing on a pair of optical systems in a spectroscopic device

The spectroscopic device 300 of the prior art is shown in Fig. 2, and the spectroscopic device 400 of Fig. 3 of the present invention is compared. Since the prior art, as shown in FIG. 2, the light splitting device 300 is assembled, the grating 310 must be docked with the substrate 320. In the case of miniaturization, there is a possibility of a junction drop and the optical waveguide pitch is different. It is assumed that the distance between the upper and lower optical waveguides is 100 μm, and the substrate 320 of the spectroscopic device 300 of the prior art has a junction drop and the optical waveguide spacing from the upper cover is 80-120 μm. The spectroscopic device 400 of the present invention is as shown in FIG. The optical waveguide pitch is fixed to 100 μm (see the schematic diagrams of FIGS. 5A and 5B, FIG. 5A is the prior art, FIG. 5B is the present invention), and the optical overall lumen efficiency when the optical signal is transmitted to the spectroscopic device by the optical tracing software simulation (Total) Flux) (%). As a result, as shown in Fig. 5C, when the optical waveguide pitch is fixed (100 μm), the optical overall lumen efficiency is the highest, and the optical waveguide pitch is different, which causes the optical overall lumen efficiency to decrease. Therefore, the two prior art dispersion device 300 when assembled as shown in the grating 310 and the substrate 320 will engage the gap resulting in reduced efficiency of the optical system, the grating arrangement of the present invention does not have this problem.

400‧‧‧ Spectroscopic device

410‧‧‧Diffraction grating device

412‧‧‧Diffing surface

414‧‧‧ first surface

416‧‧‧ second surface

417‧‧‧ third surface

418‧‧‧ side

420‧‧‧ first cover

430‧‧‧Second cover

440‧‧‧Internal space

Figure 1 is a cross-sectional view showing the structure of a prior art infrared spectrometer. 1A is a horizontal sectional view, and FIG. 1B is a vertical sectional view.

Figure 2 is a cross-sectional view of a spectroscopic device of the prior art optical system.

Figure 3 is a cross-sectional view of a spectroscopic device in accordance with a preferred embodiment of the present invention.

Figure 4 shows the effect of the surface roughness of the waveguide on the optical system in the spectroscopic device. 4A is a schematic view of a prior art spectroscopic device, and FIG. 4B is a schematic view of the spectroscopic device of the present invention. Figure 4C shows the effect of the optical overall lumen efficiency on the degree of scattering.

Figure 5 shows the effect of the optical waveguide spacing in the beam splitting device without a pair of optical systems. 5A is a schematic view of a prior art spectroscopic device, and FIG. 5B is a schematic view of the spectroscopic device of the present invention. Fig. 5C shows the case where the optical overall lumen efficiency is affected by the uneven pitch of the optical waveguide.

400‧‧‧ Spectroscopic device

410‧‧‧Diffraction grating device

412‧‧‧Diffing surface

414‧‧‧ first surface

416‧‧‧ second surface

417‧‧‧ third surface

418‧‧‧ side

420‧‧‧ first cover

430‧‧‧Second cover

440‧‧‧Internal space

Claims (12)

A diffraction grating device comprising: a first surface; a second surface and a third surface opposite to the first surface, wherein the second surface and the third surface are located in different planes, and the third surface The second surface is closer to the first surface; a side is connected between the second surface and the third surface; and a diffraction surface is connected to the first surface and the third surface between. The diffraction grating device of claim 1, wherein the diffraction surface is a concave surface. A diffraction grating device according to claim 1, which is a reflection grating. The diffraction grating device of claim 1, wherein the first surface and the third surface have a first vertical distance, and the second surface and the third surface have a second vertical distance therebetween, and The third surface has a third vertical distance between the first surface and the second surface, wherein the third vertical distance is the sum of the first vertical distance and the second vertical distance. The diffraction grating device of claim 1, wherein the material is selected from the group consisting of metal, glass, plastic, and semiconductor. A spectroscopic device comprising: the diffraction grating device of claim 1; a first cover; and a second cover, wherein the first cover system is engaged with the first surface, the second The cover system is coupled to the third surface, and the diffraction grating device, the first cover and the second cover form an internal space, and the diffraction surface faces the internal space. The spectroscopic device of claim 6, wherein the second cover is further joined to the side. The spectroscopic device of claim 6, wherein the material of the first cover is selected from the group consisting of metal, glass, plastic and semiconductor. The spectroscopic device of claim 6, wherein the material of the second cover is It is selected from the group consisting of metal, glass, plastic and semiconductor. A light splitting system comprising: an input portion for receiving an optical signal; a light splitting device as in claim 6; and an output portion. The spectroscopic system of claim 10, wherein the input portion is a slit. The spectroscopic system of claim 10, wherein the output unit comprises a photodetector.