Method, system and apparatus for hybrid optical and electrical pumping of semiconductor lasers and LEDs for improved reliability at high temperatures

• US 9,728,936 B2
• Filed: 12/19/2013
• Issued: 08/08/2017
• Est. Priority Date: 12/29/2012
• Status: Active Grant

• Current Assignee: Zephyr Photonics
• Original Assignee: Zephyr Photonics
• Inventors: Louderback, Duane
• Primary Examiner(s): Niu, Xinning
• Application Number:
  US14/135,108
• Publication Number:
  US 20150333477A1
• Time in Patent Office: 1,328 Days
• CPC Class Codes: H01S 5/0021 Degradation or life time measurements
• CPC Class Codes: H01S 5/005 Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping H01S5/026, H01S5/18388 take precedence
• CPC Class Codes: H01S 5/02251 using optical fibres
• CPC Class Codes: H01S 5/041 Optical pumping
• CPC Class Codes: H01S 5/06213 Amplitude modulation
• CPC Class Codes: H01S 5/183 having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL]
• CPC Class Codes: H04B 10/504 using direct modulation

Abstract

A method, system and an apparatus for hybrid optical and electrical pumping of semiconductor lasers and light-emitting diodes (LEDs) improves reliability at high operating temperatures. The semiconductor laser or LED is biased via optical pumping and a relatively small electrical modulation current modulates the laser. At low modulation speeds, the modulation current is substantially lower than that required for biasing the laser or directly modulating it at high speeds. The lifetime of the laser is improved by substantially reducing the operating current, enabling laser lifetimes adequate for operation in many applications, such as deep-hole oil drilling and jet engine control, where operation is not currently possible.

Claims

1. An apparatus, comprising:

a semiconductor laser source;

a pump light source located remotely relative to the semiconductor laser source wherein the pump light source produces an optical pump beam;

an optical fiber positioned between the semiconductor laser source and the pump light source wherein the optical fiber has a first end and a second end, wherein the second end is located at a distance remote from the first end;

optics arranged at the semiconductor laser source, wherein the optics are configured to couple a laser light signal from the semiconductor laser source into the first end of the optical fiber, and to couple the optical pump beam from the pump light source to the second end of the optical fiber and into the semiconductor laser source for optical pumping of the semiconductor laser source; and

an electrical current injection supplied to the semiconductor laser source, wherein the electrical current injection is configured to modulate the semiconductor laser source to generate the laser light signal,

wherein the semiconductor laser source is located at a first location and the optical pump light source is located at a second location remote from the first location, and an ambient temperature at the second location is lower than an ambient temperature at the first location.

2. The apparatus of claim 1, further comprising:

a beam splitter located adjacent the second end of the optical fiber, the beam splitter being configured and arranged to split the optical pump beam from the laser light signal.

3. The apparatus of claim 1, wherein the pump light source is a semiconductor laser having a wavelength selected to optically pump the semiconductor laser source.

4. The apparatus of claim 1, wherein the optical fiber comprises a single mode fiber, a multimode fiber, glass or polymer, or any combination thereof.

5. The apparatus of claim 1, wherein the semiconductor laser source is modulated by the electrical current injection using a digital data modulation signal or an analog data modulation signal.

6. The apparatus of claim 1, wherein the electrical current injection comprises a portion of a total bias of the semiconductor laser source.

7. The apparatus of claim 1, wherein the electrical current injection is configured to generate a current bias in the semiconductor laser source so as to reliably operate the semiconductor laser source at its ambient temperature.

8. The apparatus of claim 1, wherein the optical pump beam is configured to bias the semiconductor laser source without significantly heating the semiconductor laser source.

9. The apparatus of claim 1, wherein the semiconductor laser source comprises a laser light emitting diode (LED), a vertical-cavity surface-emitting laser (VCSEL), a Fabry-Perot laser, or a distributed feedback (DFB) laser.

17. The apparatus of claim 1, wherein the electrical current injection is configured to modulate the semiconductor laser source at a lower modulation current when modulation speed decreases.

10. A method of remotely pumping a semiconductor laser source, the method comprising:

supplying an optical pump beam generated by a pump light source to a semiconductor laser source through an optical fiber to optically pump the semiconductor laser source, the semiconductor laser source being located at a first end of the optical fiber and the optical pump light source being located at a second end of the optical fiber and remote from the first end of the optical fiber;

supplying an electrical current to the semiconductor laser source to modulate the semiconductor laser source to generate a modulated laser signal;

coupling the modulated laser signal into the first end of the optical fiber;

transmitting the modulated signal through the optical fiber from the first end of the optical fiber to the second end of the optical fiber,

wherein the semiconductor laser source is located at a first location and the optical pump light source is located at a second location remote from the first location, and an ambient temperature at the second location is lower than an ambient temperature at the first location.

11. The method of claim 10 further comprising:

coupling at least a portion of the optical pump beam from the pump light source into the optical fiber for optical pumping of the semiconductor laser source using a beam splitter disposed between the optical pump source and the second end of the optical fiber.

12. The method of claim 10, further comprising:

selecting a wavelength of the pump light source suitable for optically pumping the semiconductor laser source.

13. The method of claim 10, further comprising:

selecting a wavelength of the pump light source suitable for optically pumping the semiconductor laser source wherein the wavelength is selected to be absorbed by an active region of the semiconductor laser source.

14. The method of claim 10, further comprising:

selecting a wavelength of the pump light source suitable for optically pumping the semiconductor laser source wherein the wavelength of the pump light source is selected to be a shorter wavelength than that of the modulated laser signal emitted by the semiconductor laser source.

15. The method of claim 10, further comprising:

biasing the semiconductor laser source with optical pumping.

16. An optical link system comprising:

a semiconductor laser biased using optical pumping and directly modulated using an electrical signal to convert the electrical signal into an optical signal;

a pump light source having a wavelength for optically pumping the semiconductor laser wherein the wavelength is absorbed by an active region of the semiconductor laser and is a shorter wavelength than that of the optical signal emitted by the semiconductor laser; and

an optical fiber configured and arranged to transmit light from the pump light source to the semiconductor laser to bias the semiconductor laser via the optical pumping, wherein the optical fiber is further configured to transmit the optical signal for data transmission,

wherein the semiconductor laser source is located at a first location and the optical pump light source is located at a second location remote from the first location, and an ambient temperature at the second location is lower than an ambient temperature at the first location.