Patent ID: 8139216

Claim:
A method of positioning an optical unit in an optical package comprising a laser diode, a wavelength conversion device, and an optical unit comprising one or more optical components configured to direct light from the laser diode to the wavelength conversion device, the method comprising: providing a partially assembled optical package comprising the laser diode and the wavelength conversion device, wherein the wavelength conversion device comprises a conversion layer extending between an input face of the wavelength conversion device and an output face of the wavelength conversion device, and a waveguide portion formed in the conversion layer; coarse-positioning the optical unit in the optical package to direct light from the laser diode to the wavelength conversion device in the form of a beam spot on an input face of the wavelength conversion device; monitoring intensity of a frequency-converted optical signal output from the wavelength conversion device as the position of the optical unit is modified to 1D scan the beam spot along a portion of a crossing axis Y 1 that crosses a planar projection of the conversion layer of the wavelength conversion device; offsetting the crossing axis Y 1 and repeating the intensity monitoring step as the beam spot is 1D scanned along an offset crossing axis Y 2 ; repeating the crossing axis offset until the monitored intensity during the 1D scan meets or exceeds a crossing threshold; identifying an optimum crossing axis Y* and a corresponding optimum crossing coordinate y along the optimum crossing axis Y* by referring to respective intensity profiles of the monitored intensities; and identifying a first set of optimum coordinates x, y, z by monitoring intensity of a frequency-converted optical signal output from the wavelength conversion device as the position of the optical unit is modified to 1D scan the beam spot along a portion of one or more intersecting axes, one of which intersects the optimum crossing axis Y*.