Patent ID: 7586960

Claim:
A laser controller programmed to operate a visible light source comprising a semiconductor laser and a wavelength conversion device optically coupled to 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 I GAIN 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 I GAIN ; 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 I GAIN injected into a gain section of the semiconductor laser and modulating the drive current I GAIN to broaden the effective spectral width of the semiconductor laser, wherein the modulated drive current I GAIN forces a plurality of different emission modes to be selected in the semiconductor laser within respective ones of the encoded data periods but maintains the effective spectral width of the semiconductor laser within the FWHM wavelength conversion bandwidth of the wavelength conversion device.