Patent ID: 6813080
Filing Date: 2004-11-02
Classification: G02B

Abstract:
A metal-free reflective immersed diffraction grating for optical communications, said grating comprising:at least a first material 1 of refractive index n1 and a second material 2 of refractive index n2, wherein light from material 1 is incident on the grating; and the conditions of the following Expression (I)-(III) are met: n1>n2,â€ƒâ€ƒI n1>&lgr;/2L>n2 for single diffracted order at Littrow, andâ€ƒâ€ƒ(II) n2/n1j|<1; andâ€ƒâ€ƒ(III) wherein &lgr; is the wavelength of the light incident on the grating, &thgr;j represents any and all propagation angles of incident and diffracted light, and L is the grating period, andwherein said grating profile is located at the interface of material 1 and material 2.