Patent ID: 6332689
Filing Date: 2001-12-25
Classification: G02B,H04B

Abstract:
An apparatus comprising:a virtually imaged phased array (VIgenerator receiving an input light at a respective wavelength and producing a corresponding collimated output light traveling from the VIPA generator in a direction determined by the wavelength of the input light; anda reflecting surface reflecting the output light back to the VIPA generator, the reflecting surface having different curvatures at different positions along a direction perpendicular to a plane which includes the traveling directions of collimated output light from the VIPA generator for input light at different wavelengths, curvature c(y) of the reflecting surface being as follows: ##EQU10##where.THETA.y=is a light focusing position on the reflecting surface,.PHI.=is an input angle of the input light to the VIPA generator in air,f=is a focal length of a lens or mirror focusing the output light traveling from the VIPA generator onto the reflecting surface,a=is a depth of a center beam waist of the VIPA generator, andK is a constant so that chromatic dispersion equals -2n.sup.4 K/c.lambda., with c being the speed of light, .lambda. being wavelength, an n being a refractive index of material forming the VIPA generator.