Light source configured for stabilization relative to external operating conditions

Patent metadata

Field	Value
Publication number	US-2018145477-A1
Application number	US-201715822297-A
Country	US
Kind code	A1
Filing date	Nov 27, 2017
Priority date	Dec 18, 2015
Publication date	May 24, 2018
Grant date	—

Abstract

A laser device includes a light source that emits a source light having a first peak wavelength. A nonlinear optical component performs a frequency conversion process that converts the source light into output light having a second peak wavelength. A stabilization component minimizes a mismatch error constituting a difference between the first peak wavelength and a wavelength for which the frequency conversion process in the nonlinear optical component has a maximum value. The stabilization component may include a housing that is thermally conductive between the light source and the nonlinear optical component to minimize a temperature difference between the light source and the nonlinear optical component. The laser device may include a focusing optical component that focuses the source light to have a convergence half angle that is larger than a convergence half angle that gives maximum output power, thereby increasing an acceptable range of the mismatch error.

First claim

What is claimed is:

1 . A laser device comprising:
a light source configured to emit a source light having a first peak wavelength; and a nonlinear optical component configured to perform a frequency conversion process that converts at least a portion of the source light into output light having a second peak wavelength different from the first peak wavelength; wherein: the light source is configured such at a change in the first peak wavelength in response to a change in temperature of the laser device is more than +0.01 nm/K to a maximum of +0.06 nm/K; and the light source is configured to emit the source light having a spectral linewidth of at least 0.5 nm; and the light source and the nonlinear optical component are passively thermally conductive with each other such that a change in temperature of the light source results in a change in temperature of the nonlinear optical component.

2 . The laser device of claim 1 , wherein the non-linear optical component is configured such that the change in the first peak wavelength for which efficiency of the frequency conversion process has a maximum value in response to a change in temperature of the laser device is 0.025 nm/K.

3 . The laser device of claim 2 , wherein the light source and the nonlinear optical component are configured such that an absolute value of a difference between the change in the first peak wavelength in response to a change in temperature of the laser device and the change in first peak wavelength for which the efficiency of the frequency conversion process has a maximum value in response to a change in temperature of the laser device is less than 0.05 nm/K.

4 . The laser device of claim 1 , further comprising a focusing optical component that focuses the source light, wherein the focusing optical components is configured to focus the source light to have a first convergence half angle that is larger than a second convergence half angle that gives maximum output power of output light having the second peak wavelength.

5 . The laser device of claim 1 , further comprising a housing, wherein the housing is thermally conductive between the light source and the nonlinear optical component to minimize a temperature difference between the light source and the nonlinear optical component.

6 . The laser device of claim 5 , wherein a distance between attachment points of the light source and the nonlinear optical component to the housing is less than 200 mm.

7 . The laser device of claim 5 , wherein a thermal conductivity of material of the housing between the laser light source and the nonlinear optical component is at least 10 W·m −1 ·K −1 .

8 . The laser device of claim 5 , wherein a heat capacity of the housing between the laser light source and the nonlinear optical component is less than 500 J·K −1 .

9 . The laser device of claim 5 , wherein a heat capacity of the nonlinear optical component is less than 0.1 J·K −1 .

10 . The laser device of claim 5 , further comprising a heat sink within the housing.

11 . The laser device of claim 1 , wherein the output light includes residual light having the first peak wavelength of the source light;
the laser device further comprising an optical component configured to direct the residual light to act as a heat source for heating the nonlinear optical component as part of minimizing the mismatch error.

12 . The laser device of claim 11 , further comprising an absorbing component in thermal contact with the nonlinear optical component, wherein optical component directs the residual light onto the absorbing component and the absorbing component absorbs the residual light.

13 . The laser device of claim 11 , further comprising a filter that spatially separates the residual light from the portion of the output light having the second peak wavelength.

14 . The laser device of claim 1 , further comprising a beam stabilization optical component configured to stabilize a direction and/or position of the output light.

15 . The laser device of claim 14 , wherein the beam stabilization optical component comprises at least one of a lens, a diffraction grating, a prism, or a mirror.

16 . The laser device of claim 1 , further comprising a wavelength stabilizing component configured to reduce a variation of the first peak wavelength of the source light.

17 . The laser device of claim 16 , wherein the wavelength stabilizing component comprises a diffraction grating.

18 . The laser device of claim 1 , wherein the laser device is configured to have an operable range of ±10° C.

19 . The laser device of claim 1 , wherein the nonlinear optical component is a frequency doubling component whereby the first peak wavelength of the source light is double the second peak wavelength of the output light.

20 . The laser device of claim 19 , wherein the first peak wavelength is within a range from 400 nm to 600 nm, the second peak wavelength is within a range from 200 nm to 300 nm, and the light source is a laser diode.

Assignees

• Sharp Kk

Inventors

• Welna Karl Peter
• Boardman Edward Andrew
• Smeeton Tim Michael
• Berryman-Bousquet Valerie

Classifications

• H01S3/109 Primary

  Frequency multiplication, e.g. harmonic generation · CPC title

• H01S3/0941

  of a laser diode · CPC title

• H01S3/0405

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

• H01S3/137

  for stabilising of frequency · CPC title

• H01S3/08009

  using a diffraction grating · CPC title