# US 10,374,377 B2 · Laser medium, laser medium unit, and laser beam amplification device

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,374,377 B2
- Document ID: US10374377B2
- Status: Granted
- Kind: B2
- Application number: 15/544,613
- Filed: 2016-01-13
- Published: 2018-09-27
- Granted: 2019-08-06
- Earliest claimed: 2015-01-20
- Assignees: Hamamatsu Photonics K.K.
- Applicants: Hamamatsu Photonics K.K.
- Inventors: Takashi Sekine; Yoshinori Kato; Yoshinori Tamaoki; Takashi Kurita; Toshiyuki Kawashima; Takaaki Morita
- Web page: https://patentgrep.com/patent/US10374377B2

## CPC

- H01S 3/042: for solid state lasers {(H01S3/0401 takes precedence)}
- H01S 3/005: {Optical devices external to the laser cavity, specially adapted for lasers, e.g. for homogenisation of the beam or for manipulating laser pulses, e.g. pulse shaping (shaping laser beam for working metal or other materials B23K26/06; optical elements, systems or apparatus in general G02B)}
- H01S 3/025: {of solid state lasers, e.g. housings or mountings}
- H01S 3/0405: {Conductive cooling, e.g. by heat sinks or thermo-electric elements}
- H01S 3/0407: {Liquid cooling, e.g. by water}
- H01S 3/06: Construction or shape of active medium
- H01S 3/0604: {in the form of a plate or disc}
- H01S 3/0606: {with polygonal cross-section, e.g. slab, prism (H01S3/0604 takes precedence)}
- H01S 3/0608: {Laser crystal with a hole, e.g. a hole or bore for housing a flashlamp or a mirror}
- H01S 3/0623: {Antireflective [AR]}
- H01S 3/07: consisting of a plurality of parts, e.g. segments (H01S3/067 takes precedence)
- H01S 3/08072: {Thermal lensing or thermally induced birefringence; Compensation thereof}
- H01S 3/093: focusing or directing the excitation energy into the active medium
- H01S 3/0941: of a laser diode
- H01S 3/10: Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
- H01S 3/1611: {neodymium}
- H01S 3/1643: {YAG}
- H01S 3/091: using optical pumping
- H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL

## Abstract

A plate-like laser medium has a through-hole for providing a flow of a cooling medium. The laser medium unit includes the plurality of laser media. A laser beam amplification device includes a laser medium unit 10, an excitation light source 21 that causes excitation light to enter the laser medium unit 10, a through-hole 16a of a window member as a unit for supplying the cooling medium in a through-hole 14a of the laser medium 14, and a cooling medium flow path F1 arranged around the laser medium unit 10.

## Claims

### Claim 1

A laser medium unit including laser media, each of the laser media is a plate-like laser medium comprising a through-hole for making a cooling medium pass through the through-hole, wherein excitation light enters the laser medium from an outer peripheral surface of the laser medium, wherein
a thickness of the plate-like laser medium is from 1 mm to 20 mm, inclusive,
the laser media are stacked in the thickness direction thereof,
a ring-shaped sealing material is interposed between adjacent laser media; and
the sealing material receives pressure in the stacking direction of the laser media.

### Claim 2 (depends on 1)

The laser medium unit according to claim 1, wherein
in a case where an XYZ three-dimensional orthogonal coordinate system is set and the stacking direction of the laser media is defined as the Y axis,
there are adjacent laser media respectively having through-holes of which positions in an XZ plane are different from each other.

### Claim 3 (depends on 1)

A laser beam amplification device comprising:
the laser medium unit according to claim 1;
an excitation light source configured to cause excitation light to enter the laser medium unit;
a unit configured to supply a cooling medium in a through-hole of a plate-like laser medium of the laser media; and
a cooling medium flow path configured to be arranged around the laser medium unit;
wherein the plate-like laser medium comprises Yb-added YAG, and the added concentration of Yb in the laser medium is set from 0.1 atomic % to 10 atomic %, inclusive.