MOPA LASER SOURCE WITH WAVELENGTH CONTROL

摘要

The invention provides a wavelength-controlled pump MOPA laser and a method of operation thereof. A monolithic semiconductor MOPA laser chip has a DFB-laser based MO (master oscillator) and PA (power amplifier) sections formed in a same monolithic waveguide, and separate MO and PA electrodes for individual control of current injection into the MO and PA sections. The laser wavelength is defined by the DFB grating and is kept fixed by suitably controlling the MO current to compensate for a thermal crosstalk from the PA section, or tuned by suitably changing the MO current or direct heating of the DFB region.

主权项

1. A master oscillator-power amplifier (MOPA) device, comprising:
a monolithic MOPA chip comprising a semiconductor substrate and at least one MOPA structure formed upon the substrate, the at least one MOPA structure comprising:
a master oscillator (MO) section comprising a single spatial mode DFB laser structure for generating laser light, the single spatial mode DFB laser structure comprising a Bragg grating for providing a distributed optical feedback therein and for defining a laser wavelength, the MO section comprising a first electrical contact; anda power amplifier (PA) section comprising a semiconductor amplifier structure optically following the single spatial mode DFB laser structure and integrally coupled thereto for amplifying the laser light and for providing output light in a single spatial mode, the PA section comprising a second electrical contact,wherein the first and second electrical contacts are electrically separate from each other for separately pumping the MO and PA sections of the MOPA device with first and second electrical currents; and a MOPA driver electrically connected to the first and second electrical contacts for driving the first electrical current through the MO section and the second electrical current through the PA section to initiate lasing in the MO section at the laser wavelength while providing optical amplification in the PA section, wherein the MOPA driver comprises a controller that is configured to vary the first electrical current in dependence upon the second electrical current so that when the second electrical current through the PA section is increased for increasing the optical power of the output light, the first electrical current through the MO section is decreased so at to maintain the laser wavelength constant.