Frequency tuneable laser device

Patent metadata

Field	Value
Publication number	US-9236712-B2
Application number	US-200913132182-A
Country	US
Kind code	B2
Filing date	Dec 16, 2009
Priority date	Dec 18, 2008
Publication date	Jan 12, 2016
Grant date	Jan 12, 2016

Abstract

A frequency tuneable or chirped laser device is described that includes a laser cavity formed from a plurality of optical components. The optical components include a laser source for generating a beam of light, a spectral tuning element and one or more further optical components for directing the beam of light on to the spectral tuning element. At least one of the plurality of optical components is moveable in a first degree of freedom; such movement simultaneously altering the effective optical path length of the laser cavity and the tuning frequency of the spectral tuning element. The effective optical path length and the tuning frequency of the device are substantially insensitive to any movement of said at least one moveable optical component in degrees of freedom other than the first degree of freedom. This provides frequency tuning in which mode hopping is suppressed.

First claim

The invention claimed is:

1. A frequency tuneable laser device comprising:
a laser cavity formed from a plurality of optical components, the plurality of optical components comprising:
a laser source that generates a beam of light,
a spectral tuning element, and
one or more further optical components that directs the beam of light on to the spectral tuning element,
wherein at least one of the plurality of optical components is a moveable optical component configured to move in a first degree of freedom, the movement of said at least one moveable optical component in the first degree of freedom simultaneously altering an effective optical path length of the laser cavity and a tuning frequency of the spectral tuning element, thereby providing frequency tuning in which mode hopping is suppressed,
wherein the effective optical path length and the tuning frequency are substantially insensitive to any movement of said at least one moveable optical component in degrees of freedom other than the first degree of freedom, and
wherein the movement of the at least one moveable optical component keeps the beam of light directed on to the spectral tuning element.

2. A laser device according to claim 1 , comprising an actuator that controls movement of said at least one moveable optical component in the first degree of freedom.

3. A laser device according to claim 2 , wherein the actuator allows movement of said at least one moveable optical component that provides frequency modulation at a repetition rate greater than 50 Hz.

4. A laser device according to claim 2 , wherein the actuator comprises at least one of a flexure and a balanced oscillatory mechanical system.

5. A laser device according to claim 1 , wherein the one or more further optical components comprise one or more moveable beam steering elements that are each configured to move in a first degree of freedom, wherein movement of the one or more moveable beam steering elements in the first degree of freedom alters an angle of incidence of the beam of light on to the spectral tuning element.

6. A laser device according to claim 5 , wherein the one or more moveable beam steering elements comprise a first moveable beam steering element that is configured to move in the first degree of freedom, wherein motion of the first moveable beam steering element alone provides the simultaneous alteration of the effective optical path length and the tuning frequency.

7. A laser device according to claim 6 , wherein the one or more further optical components comprise at least one lens, wherein the first moveable beam steering element is located within a focal depth of said at least one lens.

8. A laser device according to claim 6 , wherein the first moveable beam steering element comprises a moveable mirror, wherein the beam of light is incident on the moveable mirror at an oblique angle.

9. A laser device according to claim 6 , wherein the first moveable beam steering element comprises a transmissive element.

10. A laser device according to claim 1 , wherein the first degree of freedom of movement of said at least one moveable optical component is translation along a linear axis.

11. A laser device according to claim 1 , wherein the first degree of freedom of movement of said at least one moveable optical component is rotation about an axis.

12. A laser device according to claim 1 , wherein the spectral tuning element is substantially stationary.

13. A laser device according to claim 1 , wherein the one or more further optical components collimate the beam of light that is incident on the spectral tuning element.

14. A laser device according to claim 1 , wherein the spectral tuning element comprises a diffractive optical element.

15. A laser device according to claim 1 , wherein the spectral tuning element comprises an etalon.

16. A frequency tuneable laser device, comprising:
an etalon; and
a laser diode that generates a beam of light incident on the etalon;
wherein the etalon is held substantially stationary within the laser device, and an angle of incidence of the beam of light onto the etalon is alterable; and
wherein a cavity length of the laser device and a pass frequency of the etalon are both changed when the angle of incidence of the beam of light onto the etalon is altered, thereby substantially suppressing mode hopping of the laser device.

17. A device according to claim 16 , comprising one or more additional optical components that controls the angle of incidence of the beam of light onto the etalon and an optical path length of the cavity.

Assignees

• Mcmurtry David R
• Holloway Alan J
• Renishaw Plc

Inventors

• Mcmurtry David R
• Holloway Alan J

Classifications

• H01S3/1062

  using a controlled passive interferometer, e.g. a Fabry-Perot etalon · CPC title

• H01S3/08

  Construction or shape of optical resonators or components thereof · CPC title

• H01S3/08059

  Constructional details of the reflector, e.g. shape (mirrors in general G02B5/08; mountings for mirrors G02B7/18) · CPC title

• H01S3/0813

  Configuration of resonator · CPC title

• H01S5/143 Primary

  Littman-Metcalf configuration, e.g. laser - grating - mirror · CPC title