Patent ID: 6118915
Filing Date: 2000-09-12
Classification: G02B

Abstract:
An optical device comprising:a waveguide core having a input end for a light beam to enter the waveguide core and an output end for the light beam to exit the waveguide core; andat least one slit intercepting the waveguide core between the input end and the output end for installing an optical element,wherein the waveguide core has a variable core size that is smaller at positions where the slit intercepts the waveguide core than at the input end and the output end;wherein a mode field size of the light beam in the slit is larger than mode field sizes of the light beam at the input end and output end of the waveguide core,and wherein a gap G of said slit satisfies the following formula:G<0.25 .pi.n.omega..sup.2 /.lambda.where .lambda.: is a wavelength of the light beam, n is a refractive index of the optical element in the slit and .omega. is the mode field size of the light beam in the slit.