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CN-122018126-A - Compact internal folding type long-optical-path optical cavity device

CN122018126ACN 122018126 ACN122018126 ACN 122018126ACN-122018126-A

Abstract

The invention belongs to the technical field of optical detection and discloses a compact internal folding type long-optical-path optical cavity device which comprises an external reflection unit, an internal reflection unit and a detection reflection unit, wherein the external reflection unit is used for coupling a light beam emitted by a laser unit into the internal reflection unit and coupling the light beam reflected by the internal reflection unit into the detection reflection unit, the internal reflection unit is used for carrying out repeated reflection on the light beam entering the internal reflection unit and reflecting the light beam after repeated reflection back into the external reflection unit, and the detection reflection unit is used for coupling the light beam after repeated reflection into a receiving unit.

Inventors

  • PEI LINLIN

Assignees

  • 中国民航大学

Dates

Publication Date
20260512
Application Date
20260416

Claims (8)

  1. 1. The compact inner folding type long-optical-path optical cavity device is characterized by comprising an outer reflecting unit, an inner reflecting unit and a detecting reflecting unit; the external reflection unit is used for coupling the light beam emitted by the laser unit into the internal reflection unit and can couple the light beam reflected by the internal reflection unit into the detection reflection unit; The internal reflection unit is used for carrying out multiple reflections on the light beam entering the internal reflection unit, and reflecting the light beam after multiple reflections back to the external reflection unit again; the detection reflecting unit is used for coupling the light beam after multiple reflections to the receiving unit; The internal reflection unit comprises a first large flat plate reflector (3) and a second large flat plate reflector (4), wherein the first large flat plate reflector (3) and the second large flat plate reflector (4) are arranged in parallel, a light beam multi-fold reflection area is formed between the first large flat plate reflector (3) and the second large flat plate reflector (4), the light beam is enabled to form zigzag reciprocating reflection in the light beam multi-fold reflection area, the normal line of the first large flat plate reflector (3) is arranged in a non-parallel mode with the horizontal direction, and the first large flat plate reflector (3) and the second large flat plate reflector (4) are arranged in an up-down staggered mode.
  2. 2. A compact, internally folded, long path optical cavity device according to claim 1, characterized in that the internal reflection unit further comprises a first concave mirror (1) and a second concave mirror (2), the first concave mirror (1) being arranged below the first large flat mirror (3), the second concave mirror (2) being arranged above the second large flat mirror (4), the first concave mirror (1) being arranged to reflect the light beam emerging from the light beam multiple fold reflection zone back into the light beam multiple fold reflection zone, the second concave mirror (2) being arranged to couple the incident light beam reflected by the external reflection unit into the light beam multiple fold reflection zone and to couple the light beam internally reflected back by the light beam multiple fold reflection zone to the external reflection unit.
  3. 3. A compact, internally folded, long path optical cavity device according to claim 2, characterized in that said second concave mirror (2) is a concave mirror with holes.
  4. 4. A compact, internally folded, long path optical cavity device according to claim 3, characterized in that the first concave mirror (1) and the second concave mirror (2) are arranged parallel to each other, and the normal of the first concave mirror (1) is parallel to the horizontal direction.
  5. 5. A compact, internally folded, long path optical cavity device according to claim 1, characterized in that the external reflection unit is arranged on one side of the internal reflection unit, the external reflection unit comprising a first (5) and a second (6) folded circular planar mirror, the first folded circular planar mirror (5) being located above the second folded circular planar mirror (6); The second refraction circular plane mirror (6) is used for receiving the light beam emitted by the laser unit, reflecting the light beam to the first refraction circular plane mirror (5), and reflecting the light beam reflected by the first refraction circular plane mirror (5) to the detection reflecting unit; The first turning round plane mirror (5) is used for receiving the light beam reflected by the second turning round plane mirror (6), reflecting the light beam to the internal reflection unit, and reflecting the light beam reflected by the internal reflection unit to the second turning round plane mirror (6).
  6. 6. A compact, internally folded, long path optical cavity device according to claim 5, characterized in that the normal of the first folded circular planar mirror (5) is perpendicular to the normal of the second folded circular planar mirror (6).
  7. 7. The compact, internally folded, long path optical cavity device according to claim 6, characterized in that said detection reflecting unit comprises a fold detector plane mirror (7), said fold detector plane mirror (7) being arranged below said internal reflecting unit, said fold detector plane mirror (7) being adapted to reflect the light beam reflected back by the second fold circular plane mirror (6) to said receiving unit.
  8. 8. The compact, internally folded, long path optical cavity device of claim 1, wherein the laser unit is one of a gas laser, a solid state laser, and a semiconductor laser, and the receiving unit is one of a photodiode, a charge coupled device, and a photomultiplier.

Description

Compact internal folding type long-optical-path optical cavity device Technical Field The invention relates to the technical field of optical detection, in particular to a compact internal folding type long-optical-path optical cavity device. Background Along with the increasing promotion of portable, on-site, high accuracy demands of fields such as environmental monitoring, industrial process control to check out test set, put forward higher requirement to the structural design of optical cavity, both need guarantee long enough effective optical path, reduce physical volume as far as possible, compromise light path stability and assembly convenience simultaneously. At present, the optical cavity structure for realizing long optical path in industry is mainly divided into two main flow forms of Herriott cell and White cell, and the two have obvious technical limitations in optical design and practical application. Herriott cell employs two opposing concave mirrors between which the light beam is reflected, thereby increasing the optical path. The Herriott cell is simpler in design and can achieve efficient optical path extension, but its physical dimensions are typically larger, and the cell length increases accordingly, particularly when a longer optical path is desired. White cell-a three-sided mirror design, where two smaller concave mirrors form a reflective optical path with one larger concave mirror. The reflection path of the beam between these mirrors is "V" shaped. The White cell is more suitable for use with incoherent light sources (e.g., heat radiation light sources) than the Herriott cell, but is more complex in design and difficult to manufacture and adjust. Although these cell types perform well in many applications, their physical dimensions are large and the accuracy of adjustment of the mirrors is high, so in some applications, especially where compact designs and high sensitivity are required, these techniques have certain limitations. For this purpose, a compact, inner-folded, long-path optical cavity device is proposed. Disclosure of Invention It is an object of the present invention to provide a compact, internally folded, long path optical cavity device that solves or at least alleviates one or more of the above-mentioned and other problems of the prior art. In order to achieve the above purpose, the main technical scheme adopted by the invention comprises the following steps: a compact inner folding type long-optical-path optical cavity device comprises an outer reflecting unit, an inner reflecting unit and a detecting reflecting unit; the external reflection unit is used for coupling the light beam emitted by the laser unit into the internal reflection unit and can couple the light beam reflected by the internal reflection unit into the detection reflection unit; The internal reflection unit is used for carrying out multiple reflections on the light beam entering the internal reflection unit, and reflecting the light beam after multiple reflections back to the external reflection unit again; the detection and reflection unit is used for coupling the light beam after multiple reflections to the receiving unit. In the compact internal folding long-path optical cavity device according to the invention, the internal reflection unit comprises a first large flat mirror and a second large flat mirror, the first large flat mirror and the second large flat mirror are arranged in parallel, a light beam multi-fold reflection area is formed between the first large flat mirror and the second large flat mirror, so that the light beam forms zigzag reciprocating reflection in the light beam multi-fold reflection area, and the normal line of the first large flat mirror is arranged in non-parallel with the horizontal direction. In the compact type internal folding long-optical-path optical cavity device, the first large flat reflector and the second large flat reflector are arranged in an up-and-down staggered mode. In a compact internal folding long optical path optical cavity device according to the present invention, wherein the internal reflection unit further includes a first concave mirror disposed below the first large flat mirror and a second concave mirror disposed above the second large flat mirror, the first concave mirror being configured to reflect the light beam emitted from the light beam multiple folding reflection region back into the light beam multiple folding reflection region, the second concave mirror being capable of coupling the incident light beam reflected by the external reflection unit into the light beam multiple folding reflection region and of coupling the light beam reflected back into the light beam multiple folding reflection region to the external reflection unit. In a compact, internally folded, long path optical cavity device according to the present invention, the second concave mirror is a concave mirror with an aperture. In the compact type inner folding long-o