Mirror actuator and lidar system

Abstract

A mirror actuator 1 includes: a mirror 2 that reflects a light beam emitted from a light source 110; a support body 3 that supports the mirror 2 from a rear surface 22 side; a shaft 5 to which the support body 3 is attached such that the axial direction is parallel to the reflective surface 21 of the mirror 2; and a motor 6 that causes the shaft 5 to undergo rotation or rotation-reciprocation around the axial direction of the shaft 5 in order to scan the light beam in a scanning zone 200. The mirror 2 is provided with: a base material 23; and a first dielectric multilayer film 24a that is provided on the surface of the base material 23, and in which a plurality of SiO２ films 241a formed of SiO２ and a plurality of Si films 242a formed of Si are alternately laminated.

Claims

1. A mirror actuator used to scan a scanning zone by reflecting a light beam emitted from a light source, comprising: a mirror having a reflective surface that reflects the light beam emitted from the light source and a back surface opposite to the reflective surface; a support that supports the mirror from the back surface side; a shaft to which the support is attached such that its axial direction is parallel to the reflective surface of the mirror; and a motor that rotates or reciprocates the shaft around the axial direction of the shaft in order to scan the scanning zone with the light beam, wherein the mirror comprises a base material and a SiO2 substrate provided on the surface of the base material. ２ Multiple SiO formed ２ A mirror actuator characterized by comprising a first dielectric multilayer film in which multiple Si films formed of a film and Si are alternately stacked.

2. The thickness of each of the plurality of Si films is 0.05 to 0.2 μm, and the plurality of SiO ２ The mirror actuator according to claim 1, wherein the thickness of each film is 0.1 to 0.5 μm.

3. The mirror actuator according to claim 1, wherein the angle of incidence of the light beam emitted from the light source to the mirror is in the range of 35° to 75°, and the mirror has a reflectance of 98% or more for light in the wavelength range of 1310 to 1730 nm incident within the range of 35° to 75°.

4. The mirror actuator according to claim 1, wherein the thickness of the first dielectric multilayer film of the mirror is 0.003 times or less the thickness of the substrate of the mirror.

5. The mirror actuator according to claim 1, wherein the mirror further comprises a counter film provided on the back surface of the substrate.

6. The mirror actuator according to claim 5, wherein the counter film is formed with the same film material, film structure, and film thickness as the first dielectric multilayer film.

7. The mirror actuator according to claim 1, wherein the light beam emitted from the light source is a monochromatic laser light with a wavelength of 1550 nm, and the mirror has a reflectivity of 98% or more to the monochromatic laser light.

8. The mirror actuator according to claim 1, wherein the base material of the mirror is formed of glass.

9. The mirror actuator according to claim 1, wherein the base material of the mirror is made of metal.

10. The mirror is made of SiO ２ The mirror actuator according to claim 1, further comprising a second dielectric multilayer film in which a plurality of first dielectric films formed of Si and a plurality of second dielectric films formed of a material different from Si are alternately stacked, wherein the second dielectric multilayer film is provided on the surface of the first dielectric multilayer film.

11. A light source that emits a light beam in the near-infrared wavelength range, and a mirror provided on the optical path of the light beam that reflects the light beam emitted from the light source, wherein the mirror comprises a substrate and a SiO2 material provided on the surface of the substrate. ２ Multiple SiO formed ２ A LiDAR system characterized by comprising a first dielectric multilayer film in which a film and a plurality of Si films formed of Si are alternately stacked.

12. The mirror is made of SiO ２ The LiDAR system according to claim 11, further comprising a second dielectric multilayer film in which a plurality of first dielectric films formed of Si and a plurality of second dielectric films formed of a material different from Si are alternately stacked, wherein the second dielectric multilayer film is provided on the surface of the first dielectric multilayer film.

Images