Laser element and electronic device

Patent metadata

Field	Value
Publication number	US-2024258767-A1
Application number	US-202118559511-A
Country	US
Kind code	A1
Filing date	May 26, 2021
Priority date	May 26, 2021
Publication date	Aug 1, 2024
Grant date	—

Abstract

To prevent a decrease in oscillation efficiency of laser light and a decrease in conversion efficiency of an optical wavelength due to thermal interference. A laser element includes: a laminated semiconductor layer including a first reflection layer with respect to a first wavelength and an active layer that performs surface emission at the first wavelength; a laser medium disposed on a rear side of an optical axis of the laminated semiconductor layer and including a second reflection layer with respect to a second wavelength on a first surface facing the laminated semiconductor layer and a third reflection layer with respect to the first wavelength on a second surface on a side opposite to the first surface; a fourth reflection layer with respect to the second wavelength disposed on the second surface or disposed on a rear side of the optical axis with respect to the second surface; a first resonator that causes light of the first wavelength to resonate between the first reflection layer and the third reflection layer; a second resonator that causes light of the second wavelength to resonate between the second reflection layer and the fourth reflection layer; and a heat exhaust unit that is disposed between the laminated semiconductor layer and the laser medium and exhausts heat generated in at least one of the laminated semiconductor layer or the laser medium.

First claim

1 . A laser element comprising:
a laminated semiconductor layer including a first reflection layer with respect to a first wavelength and an active layer that performs surface emission at the first wavelength; a laser medium disposed on a rear side of an optical axis of the laminated semiconductor layer and including a second reflection layer with respect to a second wavelength on a first surface facing the laminated semiconductor layer and a third reflection layer with respect to the first wavelength on a second surface on a side opposite to the first surface; a fourth reflection layer with respect to the second wavelength, the forth reflection layer being disposed on the second surface or disposed on a rear side of the optical axis with respect to the second surface; a first resonator that causes light of the first wavelength to resonate between the first reflection layer and the third reflection layer; a second resonator that causes light of the second wavelength to resonate between the second reflection layer and the fourth reflection layer; and a heat exhaust unit that is disposed between the laminated semiconductor layer and the laser medium, and exhausts heat generated in at least one of the laminated semiconductor layer or the laser medium, wherein the optical axis of the laminated semiconductor layer and an optical axis of the laser medium are coaxially arranged.

2 . The laser element according to claim 1 , wherein the heat exhaust unit includes a first member disposed between the laminated semiconductor layer and the laser medium and having a thermal conductivity higher than the laser medium.

3 . The laser element according to claim 2 , further comprising a metal layer disposed on a part or all of a surface of the first member on a side facing the laser medium and having a thermal conductivity higher than the laminated semiconductor layer and the laser medium.

4 . The laser element according to claim 2 , further comprising a second member that is bonded to a side surface of the laminated semiconductor layer, a side surface of the first member, and a side surface of the laser medium and dissipates heat transmitted to the first member.

5 . The laser element according to claim 4 , further comprising:
a substrate that supports the laminated semiconductor layer; and a bonding wire connected to a pad on the substrate and an electrode of the laminated semiconductor layer, wherein the second member is disposed to cover the side surface of the laminated semiconductor layer, the side surface of the laser medium, and the bonding wire.

6 . The laser element according to claim 4 , wherein
the first member contains at least one of sapphire or diamond, and the second member includes a metal material.

7 . The laser element according to claim 2 , further comprising a protective layer that is disposed on a surface of the first member on a side facing the laminated semiconductor layer, transmits light of the first wavelength, and reflects light of the second wavelength.

8 . The laser element according to claim 2 , wherein the first member includes a first region that transmits the light of the first wavelength, and a second region that is disposed around the first region and has a higher thermal conductivity than the laser medium.

9 . The laser element according to claim 8 , wherein the second region is an insulating material or a metal material.

10 . The laser element according to claim 8 , wherein
the second region is disposed to surround the first region, and an outer peripheral surface of the second region or a corner portion of the outer peripheral surface is located at an equal distance from a center position of the first region.

11 . The laser element according to claim 1 , further comprising a plurality of the first resonators and a plurality of the second resonators in a plane direction of the laminated semiconductor layer, the heat exhaust unit, and the laser medium.

12 . The laser element according to claim 1 , wherein the heat exhaust unit has an air gap disposed between the laminated semiconductor layer and the laser medium.

13 . The laser element according to claim 1 , further comprising a first optical element that is disposed between the second reflection layer and the fourth reflection layer, and increases a beam diameter of the light of the second wavelength.

14 . The laser element according to claim 1 , wherein the first resonator includes a second optical element that condenses the light of the first wavelength in an optical axis direction.

15 . The laser element according to claim 1 , further comprising a saturable absorber that includes a fourth reflection layer on a third surface on a side opposite to the laser medium,
wherein the optical axis of the laminated semiconductor layer, the optical axis of the laser medium, and the optical axis of the saturable absorber are coaxially arranged.

16 . The laser element according to claim 15 , wherein the laminated semiconductor layer, the laser medium, and the saturable absorber are integrally bonded.

17 . The laser element according to claim 15 , further comprising a polarization control element that is disposed between the laser medium and the saturable absorber or on a rear side of an optical axis with respect to the saturable absorber, and controls a polarization state of the light of the second wavelength.

18 . The laser element according to claim 1 , wherein the fourth reflection layer is an output coupling mirror in the second resonator.

19 . The laser element according to claim 1 , wherein
the laminated semiconductor layer includes a fifth reflection layer with respect to the first wavelength disposed on a side closer to the laser medium than the first reflection layer, and the fifth reflection layer transmits a part of the light of the first wavelength.

20 . An electronic device comprising:
a laser element; and a control unit that performs control to emit light from the laser element, wherein the laser element includes a laminated semiconductor layer including a first reflection layer with respect to a first wavelength and an active layer that performs surface emission at the first wavelength, a laser medium disposed on a rear side of an optical axis of the laminated semiconductor layer and including a second reflection layer with respect to a second wavelength on a first surface facing the laminated semiconductor layer and a third reflection layer with respect to the first wavelength on a second surface on a side opposite to the first surface, a fourth reflection layer with respect to the second wavelength, the forth reflection layer being disposed on the second surface or disposed on a rear side of the optical axis with respect to the second surface, a first resonator that causes light of the first wavelength to resonate between the first reflection layer and the third reflection layer, a second resonator that causes light of the second wavelength to resonate between the second reflection layer and the fourth reflection layer, and a heat exhaust unit that is disposed between the laminated semiconductor layer and the laser medium, and exhausts heat generated in at least one of the laminated semiconductor layer or the laser medium, and the optical axis of the laminated semiconductor layer and an optical axis of the laser medium are coaxially arranged.

Assignees

• Sony Group Corp

Inventors

• Yonezawa Gen
• Takagishi Toshiya
• Shimizu Misaki

Classifications

• H01S5/141

  using a wavelength selective device, e.g. a grating or etalon (H01S5/146 takes precedence) · CPC title

• H01S5/022

  Mountings; Housings · CPC title

• H01S3/0405

  Conductive cooling, e.g. by heat sinks or thermo-electric elements · CPC title

• H01S5/02407

  Active cooling, e.g. the laser temperature is controlled by a thermo-electric cooler or water cooling · CPC title

• H01S3/1618

  ytterbium · CPC title