US Patent 7822096 Alignment and wavelength selection in external cavity lasers

A method of operating a laser projection system is provided. The projection system comprises an external cavity laser, an optical intensity monitor, laser projection optics, and a controller. The external cavity laser comprises a laser diode, an intra-cavity wavelength conversion device, and a wavelength selective element. According to the method, the position of the wavelength selective element is adjusted relative to an optical axis Z of the external cavity laser to optimize output intensity. Specifically, the position of the wavelength selective element is adjusted by (i) tilting the wavelength selective element about its wavelength selective axis Y to reflect a wavelength of interest along an optimum path in an XZ plane of the external laser cavity and (ii) tipping the wavelength selective element about its wavelength insensitive axis X to reflect the wavelength of interest along an optimum path in a YZ plane of the external laser cavity. Additional embodiments are disclosed and claimed.