CN217687514U

CN217687514U - Small-size grating spectrometer

Info

Publication number: CN217687514U
Application number: CN202221872216.3U
Authority: CN
Inventors: 吴砺; 张建英; 周孝莲; 林磊
Original assignee: Fuzhou Photop Qptics Co ltd
Current assignee: Fuzhou Photop Qptics Co ltd
Priority date: 2022-07-15
Filing date: 2022-07-15
Publication date: 2022-10-28
Anticipated expiration: 2032-07-15

Abstract

The utility model discloses a small-size grating spectrometer, it includes circulator, 1 x N photoswitch, collimator, MEMS, beam expanding telescope, grating and high reflector along the light path direction in proper order, grating and high reflector set up relatively and form the Littman structure, are equipped with the quarter wave plate between grating and the high reflector; the optical signal is expanded by the beam expanding telescope and then incident on the grating surface in a sweepback mode. The utility model discloses a photoswitch and MEMS change the light beam direction, realize sweeping the change of inciting to grating face angle of incidence. By adopting the grazing incidence reflection grating, the size of the grating can be unchanged or increased by half the length, the requirement of improving the resolution ratio by more than 5 times can be met, and the space occupied by the light path is reduced, so that the total size of the small spectrometer is reduced.

Description

Small-size grating spectrometer

Technical Field

The utility model discloses be applied to optical fiber communication and optics technical field, specifically be a small-size grating spectrometer.

Background

The micro-spectrum scheme is various, MEMS is preferred to be used as a scanning element in an optical fiber communication system, and the whole product pursues space size minimization. The technical scheme of fig. 1 includes a circulator 01, a collimator 02, an MEMS03, a beam expanding telescope 04, a prism 05, a first transmission grating 06, a second transmission grating 07, and a total reflection mirror 08 in order along the light path direction, and two transmission gratings are adopted in the above scheme, and collimated light and the gratings are close to normal incidence or incidence at forty-five degrees, so that the total number of grating lines covered by the collimated light beam is small, and the spectral resolution is small under the condition of limited size. Because the market puts forward a higher spectral resolution requirement, if the resolution is improved on the original scheme, the size must be enlarged by several times, which is not in line with the market requirement.

Disclosure of Invention

In order to overcome the defects in the prior art, the utility model aims to provide a small-size grating spectrometer.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a small-sized grating spectrometer sequentially comprises a circulator, a 1 x N optical switch, a collimator, an MEMS (micro-electromechanical system), a beam expanding telescope, a grating and a high reflector along the light path direction, wherein the grating and the high reflector are oppositely arranged to form a Littman structure, and a quarter-wave plate is arranged between the grating and the high reflector; the optical signal is expanded by the beam expanding telescope and then incident on the grating surface in a sweepback mode.

Further, the collimator is a V-shaped groove collimator.

Further, the high reflection mirror may be replaced with a grating.

The utility model adopts the above technical scheme, through photoswitch and MEMS change beam direction, realize sweeping the change of inciting to grating face angle of incidence. By adopting the grazing incidence reflection grating, the size of the grating can be unchanged or increased by half the length, the requirement of improving the resolution ratio by more than 5 times can be met, and the space occupied by the light path is reduced, so that the total size of the small spectrometer is reduced.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments;

FIG. 1 is a schematic diagram of a conventional grating-type spectrometer;

FIG. 2 is a schematic diagram of the grating surface length expansion of incident light beam incident grazing on the grating;

fig. 3 is a schematic diagram of the present invention.

Detailed Description

As shown in fig. 3, the utility model relates to a small-sized grating spectrometer, which comprises a circulator 1, a 1 × n optical switch 2, a collimator 3, an MEMS4, a beam expanding telescope 5, a grating 6 and a high reflector 7 along the light path direction in sequence, wherein the grating 6 and the high reflector 7 are oppositely arranged to form a Littman structure, and a quarter-wave plate 8 is arranged between the grating 6 and the high reflector 7; the optical signal passes through the beam expanding telescope 5 and is incident on the surface of the grating 6 in a sweepback mode.

Wherein the collimator 3 is a V-groove collimator.

The resolution of a grating-type spectrometer depends on the total number of scribe lines that the beam strikes the grating. The width of the light beam irradiated on the grating can be expanded by adopting a mode that the light beam grazes and enters the grating surface. As shown in fig. 2, the original diameter of the beam is LO, and the scribe line length on the grating surface at normal incidence is also L0. When the light beam is inclined to an angle theta and is incident on the grating surface, the length of the grating groove which can be covered is (1/cos (theta)). Multidot.L 0. That is, when the grazing incidence angle reaches 78.47 °, the total length of the covered grating lines is 5 × l0; when the grazing incidence angle is 84.27 °, the total length covered by the grating lines reaches 10 × l0.

Because MEMS turned angle is limited, the biggest facula size that allows is limited, so the utility model discloses adopt the telescope that expands beam, simultaneously, expand beam telescope's the multiple M that expands, also be the multiple that the MEMS reverberation passes through the telescope and reduces, wherein M = cos alpha/cos beta. And meanwhile, a 1 × N optical switch is introduced to increase the variation of the total reflection angle of the MEMS.

Wherein the high-reflection mirror can be replaced by other gratings.

The utility model discloses a quarter wave plate is because the p of grating is different with s component reflectivity, can eliminate PDL like this.

If the glancing angle is larger, the resolution is improved more, or the beam diameter is expanded more, and the resolution is improved more. The utility model discloses a glancing incidence reflection grating, grating size can be unchangeable or increase half length, can satisfy resolution ratio and promote the demand more than 5 times, has reduced the shared space of light path to reduce the total size of small-size spectrum appearance.

The practice of the present invention has been described with reference to the accompanying drawings, but the invention is not limited to the embodiments described above, which are illustrative rather than limiting, and it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the embodiments of the present invention, and they should be construed as being included in the scope of the claims and description of the present invention.

Claims

1. A small-size grating spectrometer which characterized in that: the optical path direction of the device sequentially comprises a circulator, a 1 x N optical switch, a collimator, an MEMS (micro-electromechanical system), a beam expanding telescope, a grating and a high reflector, wherein the grating and the high reflector are oppositely arranged to form a Littman structure, and a quarter-wave plate is arranged between the grating and the high reflector; the optical signal is expanded by the beam expanding telescope and then incident on the grating surface in a sweepback mode.

2. The compact grating spectrometer of claim 1, wherein: the collimator is a V-shaped groove collimator.

3. The compact grating spectrometer of claim 1, wherein: the high-reflection mirror may be replaced with a grating.