Laser-Driven Light Source with Electrodeless Ignition

Patent metadata

Field	Value
Publication number	US-2023420242-A1
Application number	US-202318465022-A
Country	US
Kind code	A1
Filing date	Sep 11, 2023
Priority date	May 24, 2021
Publication date	Dec 28, 2023
Grant date	—

Abstract

An electrodeless laser-driven light source includes a laser that generates a CW sustaining light. A pump laser generates pump light. A Q-switched laser crystal receives the pump light generated by the pump laser and generates pulsed laser light at an output in response to the generated pump light. A first optical element projects the pulsed laser light along a first axis to a breakdown region in a gas-filled bulb comprising an ionizing gas. A second optical element projects the CW sustaining light along a second axis to a CW plasma region in the gas-filled bulb comprising the ionizing gas. A detector detects plasma light generated by a CW plasma and generates a detection signal at an output. A controller generates control signals that control the pump light to the Q-switched laser crystal so as to extinguish the pulsed laser light within a time delay after the detection signal exceeds a threshold level.

First claim

1 - 43 . (canceled)

44 . A method of generating light with a laser-driven light source, the method comprising:
a) generating a continuous wave (CW) sustaining light; b) propagating the CW sustaining light to a gas filled bulb comprising an ionizing gas; c) generating pump light; d) irradiating a Q-switched laser crystal with the generated pump light, thereby generating pulsed laser light; e) propagating the generated pulsed laser light to the gas filled bulb comprising the ionizing gas, thereby generating a CW plasma that emits light; f) detecting light generated by the CW plasma in the gas filled bulb comprising the ionizing gas; and g) controlling the pump light so as to extinguish the pulsed laser light after the light generated by the CW plasma is detected.

45 . The method of claim 44 wherein a pulse repetition rate of the pulsed laser light is in a range of 1 kHz to 20 kHz.

46 . The method of claim 44 wherein a pulse repetition rate of the pulsed laser light is less than or equal to 1 kHz.

47 . The method of claim 44 wherein a pulse energy of the pulsed laser light is in a range of 50 μJoules to 500 μJoules.

48 . The method of claim 44 wherein a pulse energy of the pulsed laser light is in a range of 500 μJoules to 5 mJoules.

49 . The method of claim 44 wherein a pulse duration of the pulsed laser light is in a range of 0.1 ns to 10 ns.

50 . The method of claim 44 wherein a power of the CW sustaining light is in a range of 5 W to 50 W.

51 . The method of claim 44 wherein a power of the CW sustaining light is in a range of 5 W to 1500 W.

52 . The method of claim 44 wherein the generating pulsed laser light by irradiating the Q-switched laser crystal comprises providing optical gain.

53 . The method of claim 44 wherein the generating pulsed laser light by irradiating the Q-switched laser crystal comprises providing saturable absorption.

54 . The method of claim 44 wherein the generating pulsed laser light by irradiating the Q-switched laser crystal further comprises narrow-band filtering.

55 . The method of claim 54 further comprising reflecting at least some of the plasma light.

56 . The method of claim 54 wherein the narrow-band filter blocks wavelengths in a spectrum generated by the gas in the gas-filed bulb.

57 . The method of claim 44 wherein a pressure in the gas-filled bulb comprises a pressure in a range of 20 atm to 50 atm.

58 . The method of claim 44 wherein the controlling the pump light so as to extinguish the pulsed laser light is performed within a time delay after the light generated by the CW plasma is detected.

59 . The method of claim 44 wherein the controlling the pump light so as to extinguish the pulsed laser light comprises extinguishing the pump light.

Assignees

• Hamamatsu Photonics Kk
• Energetiq Tech Inc

Inventors

• PARTLOW Matthew
• Smith Donald K
• Besen Matthew
• ASAI Akinori

Classifications

• H01J61/54 Primary

  Igniting arrangements, e.g. promoting ionisation for starting · CPC title

• H01S3/1115

  using intracavity saturable absorbers · CPC title

• H01S3/094038

  End pumping · CPC title

• H01J65/00

  Lamps without any electrode inside the vessel; Lamps with at least one main electrode outside the vessel · CPC title

• H01S3/0912

  Electronics or drivers for the pump source, i.e. details of drivers or circuitry specific for laser pumping (laser diode drivers H01S5/042) · CPC title