Laser system and method of tuning the output power of the laser system

Patent metadata

Field	Value
Publication number	US-10305252-B2
Application number	US-201515510870-A
Country	US
Kind code	B2
Filing date	Oct 8, 2015
Priority date	Oct 15, 2014
Publication date	May 28, 2019
Grant date	May 28, 2019

Abstract

A power control method for a laser system comprising laser diodes arranged in diode banks is provided. Each diode bank comprises at least one of the laser diodes and has a maximum power. The method comprises operating a first diode bank of the diode banks to output a first power; and concurrently operating other of the diode banks to output other powers, at least one of the other powers being different than the first power.

First claim

What is claimed is:

1. A laser system comprising:
diode banks configured to:
output laser beams,
each of the diode banks including a laser diode; and

a control unit configured to:
receive an indication of a requested power;
selectively operate, based on the requested power requiring a transition from a current power level to a different power level, a plurality of the diode banks,
a first plurality of diode banks being operated when the different power level is less than the current power level, or
a second plurality of diode banks being operated when the different power level is greater than the current power level,
the second plurality of diode banks including a quantity of diode banks that is greater than a quantity of diode banks included in the first plurality of diode banks; and

operate, after selectively operating the first plurality of diode banks, the second plurality of diode banks when the requested power exceeds a maximum power of the first plurality of diode banks; or
operate, after selectively operating the second plurality of diode banks, the first plurality of diode banks when the requested power does not exceed a minimum power of the second plurality of diode banks.

2. The laser system of claim 1 , wherein, when the requested power equals a maximum power of a first diode bank of the diode banks, a first power equals the maximum power of the first diode bank, and second powers equal zero.

3. The laser system of claim 1 , wherein
each of the diode banks has a maximum power,
the laser system has a system maximum power equal to a sum of the maximum power of each of the diode banks,
a first current control signal is configured to tune a first diode bank, of the diode banks, over a broad range that is broader than 50% of the maximum power of the first diode bank, and
other current control signals are configured to tune second diode banks, of the diode banks, over restricted ranges that are narrower than 50% of their respective maximum powers.

4. The laser system claim 3 , wherein the broad range comprises 40% to 100% of the maximum power of the first diode bank.

5. The laser system of claim 3 , wherein the restricted ranges comprise 70% to 100% of respective maximum powers of the second diode banks.

6. The laser system of claim 3 , wherein the broad range comprises 10% to 100% of the maximum power of the first diode bank.

7. The laser system of claim 3 , wherein the maximum power of one of the diode banks is different than the maximum power of another of the diode banks.

8. The laser system of claim 3 , wherein the maximum power of the first diode bank is greater than the maximum power of each of the second diode banks.

9. The laser system of claim 1 , wherein the laser system comprises a direct-diode laser.

10. The laser system of claim 1 , wherein the laser diode is a single-emitter laser diode or a multi-emitter laser diode.

11. The laser system of claim 1 , further comprising:
a current controller configured to:
receive current control signals corresponding to each of the diode banks; and
enable current flows to the diode banks based on the current control signals.

12. The laser system of claim 10 , wherein the multi-emitter laser diode comprises a laser-diode bar or a vertical cavity surface-emitting laser (VCSEL) array.

13. The laser system of claim 1 , wherein the laser diode is located in a laser-diode module that includes at least two laser diodes having outputs at least one of spatially combined or polarization combined.

14. The laser system of claim 1 , further comprising:
a diode-pumped laser system coupled to a laser gain medium,
wherein an output power of the diode-pumped laser system is configured to pump the laser gain medium,
the laser gain medium comprises one of a fiber laser, a disk laser, a slab laser, a rod laser, a diode-pumped solid-state laser, a Raman laser, a Brillouin laser, an optical parametric laser, or an alkali-vapor laser.

15. The laser system of claim 1 , wherein the diode banks include a first diode bank, second diode banks, and at least one third diode bank.

16. The laser system of claim 1 , further comprising:
a temperature control unit configured to control a temperature of the laser diode as a function of a modulation frequency.

17. The laser system of claim 16 , wherein
a first diode bank, of the diode banks, comprises a support structure on which the laser diode is mounted, and
the temperature control unit includes an electrically resistive element coupled to the support structure and configured to heat the support structure.

18. A power control method for a laser system comprising laser diodes arranged in diode banks, each diode bank comprising at least one of the laser diodes and having a maximum power, the method comprising:
receiving, by a control unit, an indication of a requested power;
selectively operating, by the control unit and based on the requested power requiring a transition from a current power level to a different power level, a plurality of the diode banks,
a first plurality of diode banks being operated when the different power level is less than the current power level, or
a second plurality of diode banks being operated when the different power level is greater than the current power level,
the second plurality of diode banks including a quantity of diode banks that is greater than a quantity of diode banks included in the first plurality of diode banks; and

operating, after selectively operating the first plurality of diode banks, the second plurality of diode banks when the requested power exceeds a maximum power of the first plurality of diode banks; or
operating, after selectively operating the second plurality of diode banks, the first plurality of diode banks when the requested power does not exceed a minimum power of the second plurality of diode banks.

19. The power control method of claim 18 , wherein a first power, associated with a first diode bank of the diode banks, comprises a requested power to be output by the laser system, and second powers, associated with second diode banks of the diode banks, equal zero.

20. The power control method of claim 19 , wherein operating a diode bank, of the diode banks, to output zero power comprises applying a current to the diode bank which is less than a threshold current of the at least one of the laser diodes.

21. The power control method of claim 18 , wherein
each diode bank has a maximum power,
the laser system has a system maximum power equal to a sum of the maximum power of each of the diode banks,
a first diode bank, of the diode banks, is tuned over a range greater than 50% of the maximum power of the first diode bank, and
second diode banks, of the diode banks, are tuned over a range comprising less than 50% of their respective maximum powers.

22. The power control method of claim 18 , wherein
a range of a first diode bank, of the diode banks, comprises 0% to 100% of a maximum power of the first diode bank, and
second diode banks, of the diode banks, are tuned above 70% of their respective maximum powers.

23. The power control method of claim 18 , wherein a maximum power of a first diode bank, of the diode banks, is greater than a maximum power of each of second diode banks of the diode banks.

24. The power control method of claim 18 , wherein a maximum power of a first diode bank, of the diode banks, is smaller than a maximum power of each

Assignees

• Lumentum Operations Llc
• Amada Holdings Company Ltd

Inventors

• Muendel Martin H
• Franke Justin L
• Alonis Joseph J
• Usuda Kaori
• Ogata Minoru

Classifications

• B23K26/064

  by means of optical elements, e.g. lenses, mirrors or prisms · CPC title

• B23K26/38

  by boring or cutting · CPC title

• H01S5/4025

  Array arrangements, e.g. constituted by discrete laser diodes or laser bar (H01S5/42 takes precedence) · CPC title

• H01S5/0427 Primary

  for applying modulation to the laser · CPC title

• H01S5/0071

  for beam steering, e.g. using a mirror outside the cavity to change the beam direction · CPC title