Wavelength-stabilized semiconductor laser source

• Main Author: Blauvelt, Henry A
• Format: Patent
• Language: English
• Published: 10.03.2020
• Subjects: BASIC ELECTRIC ELEMENTS; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; DEVICES USING STIMULATED EMISSION; ELECTRICITY; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF

A semiconductor laser source includes a partial-grating DFB laser with two laser electrodes, one over the grating and the other between the grating and one end of the laser. Constant laser currents flow into the waveguide through the electrodes (typically different from each other) and produce laser output. A wavelength discriminator, an optical detector, and a wavelength-control circuit act as a wavelength-control feedback mechanism to generate a wavelength control current that flows through one laser electrode or the other, or through both electrodes with opposite polarities. Phase noise on the laser output can be reduced at modulation frequencies exceeding several hundred kHz up to one or several tens of MHz or more. The laser-wavelength can be swept while exhibiting reduced phase noise.