Forced wavelength chirping in semiconductor lasers
AssigneeCorning Incorporated
InventorMartin Hai Hu
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Abstract
Methods of controlling semiconductor lasers are provided where, the time-averaged optical spectrum of the semiconductor laser is broadened by modulating the drive current at a relatively high frequency. Generally, the frequency of the drive current modulation is high enough to induce wavelength chirping within the data periods encoded in the gain current signal. Laser controllers and projections systems operating according to the disclosed methodology are also provided.
Claims20
A method of controlling a semiconductor laser, the method comprising:
- configuring the semiconductor laser for optical emission of encoded data characterized by a plurality of encoded data periods, at least one parameter of the optical emission being a function of a drive current IGAIN injected into a gain section of the semiconductor laser;
- and
- broadening the time-averaged optical spectrum of the semiconductor laser by modulating the drive current, wherein the frequency of the drive current modulation is such that a plurality of different emission modes are selected in the semiconductor laser within respective ones of the encoded data periods.
A laser controller programmed to operate a semiconductor laser, wherein the controller is programmed such that at least the following conditions apply to the operation of the semiconductor laser:
- the laser controller comprises at least one output for a drive current IGAIN to be injected into the gain section of the semiconductor laser;
- the laser controller is programmed to control at least one parameter of the semiconductor laser at least partially in response to the drive current IGAIN;
- and
- the laser is further programmed to alter mode selection in the semiconductor laser by configuring the semiconductor laser for optical emission of encoded data characterized by a plurality of encoded data periods, at least one parameter of the optical emission being a function of a drive current IGAIN injected into a gain section of the semiconductor laser and broadening the time-averaged optical spectrum of the semiconductor laser by modulating the drive current, wherein the frequency of the drive current modulation is such that a plurality of different emission modes are selected in the semiconductor laser within respective ones of the encoded data periods.
A laser projection system comprising at least one semiconductor laser and a laser controller programmed to operate the semiconductor laser wherein the controller is programmed such that at least the following conditions apply to the operation of the semiconductor laser:
- the laser controller comprises at least one output for a drive current IGAIN to be injected into the gain section of the semiconductor laser;
- the laser controller is programmed to control at least one parameter of the semiconductor laser at least partially in response to the drive current IGAIN;
- and
- the laser is further programmed to alter mode selection in the semiconductor laser by configuring the semiconductor laser for optical emission of encoded data characterized by a plurality of encoded data periods, at least one parameter of the optical emission being a function of a drive current IGAIN injected into a gain section of the semiconductor laser and broadening the time-averaged optical spectrum of the semiconductor laser by modulating the drive current, wherein the frequency of the drive current modulation is such that a plurality of different emission modes are selected in the semiconductor laser within respective ones of the encoded data periods.
Dependencies are inferred from the claim text.