CN-224216966-U - Thermo-optic crystal depolarizer

Abstract

The utility model relates to a thermo-optic crystal depolarizer, which comprises a laser source and a flat sheet positioned in the beam propagation direction of the laser source, wherein the flat sheet is formed by thermo-optic birefringent crystals sensitive to temperature, two opposite side surfaces of the flat sheet are parallel to each other and perpendicular to a light passing surface, a heating plate is arranged on one side surface of the flat sheet, a refrigerating plate is arranged on the other side surface of the flat sheet, and under the heat exchange effect of the heating plate and the refrigerating plate, temperature difference is formed on the two side surfaces of the flat sheet, so that different positions on the flat sheet have different phase delays, and polarization states of different positions of the light beams are different after passing through the flat sheet, thereby realizing depolarization. The depolarizer with the structure can be manufactured in a wide wavelength range at low cost, and the temperature gradient difference can realize a dynamic adjusting function.

Inventors

• WU LI
• ZHENG BAOZHONG
• XU YUNBING
• CHEN LIXUN
• ZHAO WULI
• LI YANG

Assignees

• 福州高意通讯有限公司

Dates

Publication Date

20260508

Application Date

20250526

Claims (3)

1. 1. A thermo-optic crystal depolarizer is characterized by comprising a laser source and a flat sheet positioned in the beam propagation direction of the laser source, wherein the flat sheet is formed by thermo-optic birefringent crystals sensitive to temperature, two opposite side surfaces of the flat sheet are parallel to each other and perpendicular to a light passing surface, a heating plate is arranged on one side surface of the flat sheet, a refrigerating plate is arranged on the other side surface of the flat sheet, and under the heat exchange effect of the heating plate and the refrigerating plate, temperature difference is formed on the two side surfaces of the flat sheet, so that different positions on the flat sheet have different phase delays, and polarization states of different positions of the light beams are different after passing through the flat sheet, so that depolarization is realized.
2. 2. The thermo-optic crystal depolarizer of claim 1, wherein the two flat plates have optical axes at an angle of 45 degrees.
3. 3. The thermo-optic crystal depolarizer of claim 1, wherein the flat sheet is lithium niobate, lithium tantalate, yttrium vanadate or KDP.

Description

Thermo-optic crystal depolarizer Technical Field The utility model relates to the technical field of depolarizers, in particular to a thermo-optic crystal depolarizer. Background Since 1808 Malus discovered polarization of light, various polarization devices have been invented, and have been widely used in various fields of human life. In other cases, however, polarized light is undesirable because it is prone to measurement errors, which require depolarization of the polarized light to change it to unpolarized light. The depolarizer is a device for changing polarized light into unpolarized light, can effectively eliminate measurement errors caused by polarization, and solves the problem of polarization-related loss in an optical fiber communication system and a measuring instrument. The most commonly used depolarizer implementation method at present is a double-wedge-angle birefringent crystal structure, which is suitable for multi-wavelength depolarization. There is no new conceptual breakthrough in designs of depolarizers over the past decades. Disclosure of Invention The utility model aims to overcome the defects of the prior art and provides a thermo-optic crystal depolarizer. In order to achieve the above purpose, the present utility model adopts the following technical scheme: A thermo-optic crystal depolarizer comprises a laser source and a flat sheet positioned in the beam propagation direction of the laser source, wherein the flat sheet is formed by thermo-optic birefringent crystals sensitive to temperature, two opposite side surfaces of the flat sheet are parallel to each other and perpendicular to a light-passing surface, a heating plate is arranged on one side surface of the flat sheet, a refrigerating plate is arranged on the other side surface of the flat sheet, and under the heat exchange effect of the heating plate and the refrigerating plate, temperature differences are formed on the two side surfaces of the flat sheet, so that different positions on the flat sheet have different phase delays, and polarization states of different positions of the light beams are different after passing through the flat sheet, so that depolarization is realized. Further, the number of the flat sheets is two, and the optical axes of the two flat sheets form an included angle of 45 degrees. Further, the flat sheet is lithium niobate, lithium tantalate, yttrium vanadate or KDP. The utility model adopts the technical proposal and has the beneficial effects that: The utility model adopts the thermo-optic crystal flat sheet sensitive to temperature, and the phase delay of different positions of the thermo-optic crystal is different by applying the temperature gradient difference on the thermo-optic crystal flat sheet, and the polarization states of different positions of the light beam are different after passing through the thermo-optic crystal, thereby realizing depolarization, being capable of being manufactured into a depolarizer with a wide wavelength range at low cost, and realizing the dynamic adjustment function by the temperature gradient difference. Drawings The utility model is described in further detail below with reference to the attached drawings and detailed description: FIG. 1 is a schematic diagram illustrating phase retardation using a quartz wave half-wave plate; FIG. 2 is a schematic diagram of a thermo-optic crystal depolarizer according to the present utility model; FIG. 3 is a schematic diagram of another embodiment of a thermo-optic crystal depolarizer of the present utility model; Fig. 4 is a schematic view of two flat optical axes forming an angle of 45 degrees. Detailed Description As shown in FIG. 1, a quartz wave plate is first used as an example, and at normal temperature, a light beam is linearly polarized at a position A, a position B is delayed by 90 degrees from the position A in phase, and the polarization state is rotated. After the quartz wave plate half-wave plate is heated to a certain temperature, the phase delay of the quartz wave plate half-wave plate exceeds the half-wave plate state, so that polarized light is not rotated by 90 degrees any more. The quartz wave plate is changed into a thermal optical crystal sensitive to temperature, and a temperature gradient difference is applied to the thermal optical crystal, so that the phase delays of different positions of the thermal optical crystal are different, and the polarization states of different positions of the light beam are different after passing through the crystal, thereby realizing depolarization. Specifically, as shown in fig. 2, the thermo-optical crystal depolarizer of the present utility model includes a laser source 1 and a flat sheet 2 located in the beam propagation direction of the laser source 1, wherein the flat sheet 2 is formed by a thermo-optical birefringent crystal sensitive to temperature, and the birefringent crystal may be lithium niobate, lithium tantalate, yttrium vanadate or KDP. The two op