IP Library Granted Patent US 12671223
Granted Patent B2
US 12671223 · App. 17/971,042 · Granted Jun 30, 2026

Laser apparatus and method

Inventors: Chang-Qing Xu (Dundas, CA); Liam Flannigan (Hamilton, CA); Joshua Kneller (Hamilton, CA)
Assignee: McMaster University
H01S3/0092G02F1/353H01S3/09415H01S3/1083H01S3/109
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Quick Facts
Patent No.
US 12671223
App. No.
17/971,042
Granted
Jun 30, 2026
Kind
B2
Abstract

A narrow linewidth mid infrared laser, including a pumping laser diode with a fast-axis compressor and a pumping wavelength λ o ; and an optical resonator arranged to receive the pumping wavelength λ o , the optical resonator including a laser crystal with a lasing wavelength λ p , a dichroic mirror, and a nonlinear crystal to generate an idler wavelength λ i .

Claims (35)

1 . A narrow linewidth mid infrared laser, comprising:

a. a pumping laser diode with a fast-axis compressor and configured to generate a lasing light at a lasing wavelength λ o ; and

b. an optical resonator arranged to receive the lasing light at the pumping lasing wavelength λ o , the optical resonator including a laser crystal that is configured to receive the lasing light and to generate a pumping light at a pumping wavelength λ p , a dichroic mirror, and a nonlinear crystal configured to receive the pumping light and to generate an idler light at an idler wavelength λ i and to generate a signal light at a signaling wavelength λ s , wherein the idler light travels in an opposite direction to the signal light and the pumping light;

wherein the nonlinear crystal is configured with an orientation patterned semiconductor that has a period of Λ and a respective refractive index np, ns, ni at corresponding wavelengths, and the period Λ is determined based on a quasi-phase matched condition 1/Λ=np/λ p −−ns/λ s +ni/λ i and an energy conservation condition of backward optical parametric oscillation 1/λ p =1/λ s +1/λ i .

2 . The laser of claim 1 , wherein an input facet of the laser crystal is coated with a first coating that is a high transmission coating at the lasing wavelength λ o and a high reflective coating at the pumping wavelength λ p ; and an output facet of the laser crystal is coated with a second coating that is an anti-reflective coating at the pumping wavelength λ p .

3 . The laser of claim 1 , wherein the dichroic mirror is selected to have a nearly zero loss at the pumping wavelength λ p and a high reflection at the idler wavelength λ i .

4 . The laser of claim 1 , wherein the nonlinear crystal includes an input facet coated with a third coating that is an anti-reflective coating at the pumping wavelength λ p and a high transmission coating at the idler wavelength λ i ; and an output facet coated with a fourth coating that is a high reflective coating at the pumping wavelength λ p .

5 . The laser of claim 1 , further comprising two electrodes mounted to the nonlinear crystal.

6 . A method of tuning the idler wavelength λ i , comprising generating the pumping wavelength λ p using the laser of claim 5 ; and applying a voltage to the nonlinear crystal using the two electrodes.

7 . A method of tuning the idler wavelength λ i , comprising generating the pumping wavelength λ p using the laser of claim 5 ; and applying a current through the nonlinear crystal using the two electrodes.

8 . A narrow linewidth mid infrared laser, comprising:

a. a pumping laser diode with a fast-axis compressor and configured to generate a lasing light at a lasing wavelength λ o ; and

b. an optical resonator arranged to receive the lasing light at the lasing wavelength λ o , the optical resonator including a laser crystal that is configured to receive the lasing light and to generate a pumping light at a pumping wavelength λ p , and a nonlinear crystal configured to receive the pumping light and to generate an idler light at an idler wavelength λ i and to generate a signal light at a signaling wavelength λ s , wherein the idler light travels in an opposite direction to the signal light and the pumping light;

wherein the nonlinear crystal is configured with an orientation patterned semiconductor that has a period of Λ and a respective refractive index np, ns, ni at corresponding wavelengths, and the period Λ is determined based on a quasi-phase matched condition 1/Λ=np/λ p −ns/λ s +ni/λ i and an energy conservation condition of backward optical parametric oscillation 1/λ p =1/λ s +1/λ i ; and

c. an optical filter arranged to receive the idler light at the idler wavelength λ i from an outlet facet of the nonlinear crystal.

9 . The laser of claim 8 , wherein an input facet of the laser crystal is coated with a first coating that is a high transmission coating at the lasing wavelength λ o and a high reflective coating at the pumping wavelength λ p ; and an output facet of the laser crystal is coated with a second coating that is an anti-reflective coating at the pumping wavelength λ p .

10 . The laser of claim 8 , wherein the nonlinear crystal includes an input facet coated with a third coating that is an anti-reflective coating at the pumping wavelength λ p and a high transmission coating at the idler wavelength λ i ; and an output facet coated with a fourth coating that is a high reflective coating at the pumping wavelength λ p and an anti-reflective or high transmittance coating at the idler wavelength λ i .

11 . The laser of claim 8 , wherein the optical filter has nearly zero loss at the idler wavelength λ i and high rejection at the pumping wavelength λ p and a signal wavelength λ s that is also generated by the nonlinear crystal.

12 . The laser of claim 8 , further comprising two electrodes mounted to the nonlinear crystal.

13 . A method of tuning the idler wavelength λ i , comprising generating the pumping wavelength λ p using the laser of claim 12 ; and applying a voltage to the nonlinear crystal using the two electrodes.

14 . A method of tuning the idler wavelength λ i , comprising generating the pumping wavelength λ p using the laser of claim 12 ; and applying a current through the nonlinear crystal using the two electrodes.

15 . A high power mid infrared laser, comprising:

a. a pumping laser diode with a fast-axis compressor and configured to generate a lasing light at a lasing wavelength λ o ; and

b. a first optical resonator arranged to receive the lasing light at the lasing wavelength λ o , the first optical resonator including a laser crystal that is configured to receive the lasing light and to generate a pumping light at a lasing pumping wavelength λ p , a dichroic mirror, and a nonlinear crystal configured to receive the pumping light and to generate an idler light at an idler at an idler wavelength λ i and a signal light at a signal wavelength λ s , wherein the idler light travels in an opposite direction to the signal light and the pumping light;

wherein the nonlinear crystal is configured with an orientation patterned semiconductor that has a period of Λ and a respective refractive index np, ns, ni at corresponding wavelengths, and the period Λ is determined based on a quasi-phase matched condition 1/Λ=np/λ p −ns/λ s −ni/λ i and an energy conservation condition of forward optical parametric oscillation 1/λ p =1/λ s +1/λ i ; and

c. a second optical resonator arranged to confine the signal light at the signal wavelength λ s , the second optical resonator including a second mirror, a narrow bandwidth optical filter, the dichroic mirror, and the nonlinear crystal.

16 . The laser of claim 15 , wherein the laser crystal includes an input facet coated with a first coating that is a high transmission coating at the lasing wavelength λ o and a high reflective coating at the pumping wavelength λ p , and an output facet coated with a second coating that is an anti-reflective coating at the pumping wavelength λ p .

17 . The laser of claim 15 , wherein the nonlinear crystal includes an input facet coated with a third coating that is an anti-reflective coating at the pumping wavelength λ p , an anti-reflection coating at the signal wavelength λ s , a high reflection at the idler wavelength λ i ; and an output facet coated with a fourth coating that is a high reflective coating at the pumping wavelength λ p , and a high reflection coating at the signal wavelength λ s , and an anti-reflection or high transmittance coating at the idler wavelength λ i .

18 . The laser of claim 15 , wherein the dichroic mirror has nearly zero loss at the pumping wavelength λ p and high reflection at the signal wavelength λ s .

19 . The laser of claim 15 , wherein the narrow bandwidth optical filter has nearly zero loss at the signal wavelength λ s and high rejection at the pumping wavelength λ p and the idler wavelength λ i .

20 . The laser of claim 15 , wherein the second mirror has high reflection at the signal wavelength λ s .

21 . The laser of claim 15 , wherein the second optical resonator further comprises a high speed optical modulator.

22 . The laser of claim 15 , further comprising two electrodes mounted to the nonlinear crystal.

23 . A method of tuning the idler wavelength λ i , comprising generating the pumping wavelength λ p using the laser of claim 22 ; and applying a voltage to the nonlinear crystal using the two electrodes.

24 . A method of tuning the idler wavelength λ i , comprising generating the pumping wavelength λ p using the laser of claim 22 ; and applying a current through the nonlinear crystal using the two electrodes.