Patent ID: 6628861
Filing Date: 2003-09-30
Classification: G02B

Abstract:
A tunable apparatus for controlling light transmitted in a waveguide comprising:a waveguide to guide light; a periodic grating coupled to the waveguide to cause an induced grating in the waveguide; a second periodic grating, having a grating periodicity different from the periodic grating, and coupled to the waveguide to cause a second induced grating in the waveguide that is at least partially overlap with the induced grating to effectuate a combination grating that has a grating period less than grating periods of the induced grating and the second induced grating; and a coupling device to couple the waveguide to the periodic grating and the second periodic grating to allow for the periodic grating to be adjustable in position along the waveguide relative to the second period grating to change the grating period of the combination grating in the waveguide.