Patent ID: 6040944
Filing Date: 2000-03-21
Classification: G02B

Abstract:
A method for tuning an optical filter system, the filter system including a first filter and a second filter, the first filter having a surface and transmitting or reflecting light along a normal to the surface in a first wavelength range, the second filter reflecting or transmitting light in a target wavelength range, the method comprising;directing light toward the first filter so that the light is incident upon the surface at an angle, and so that the first filter transmits or reflects a portion of the incident light which is within a second wavelength range;displacing the second wavelength range independently of the target wavelength range by rotating the first filter relative to the second filter and about an axis which is oblique to the incident light, and which is also oblique to the normal to the surface of the first filter to change the incident angle, wherein the first filter is rotated with a collimator assembly, wherein a GRIN lens of the collimating assembly is substantially coaxial with the axis of rotation, andmonitoring the second wavelength range from the first filter and terminating the rotating step when the second wavelength range is aligned with the target wavelength range.