Patent ID: 6504975
Filing Date: 2003-01-07
Classification: G02B,H01S

Abstract:
A coupling lens used for coupling a beam of light emitted from a semiconductor laser to an optical fiber,wherein the coupling lens is formed of a single lens, a diffraction lens formed of concentric zones is integrated on either one of an incident surface and an exit surface of the single lens, the diffraction lens has a positive refracting power, a relief function of the diffraction lens has an approximately isosceles triangular shape, and a depth W of the relief function satisfies the following formula: 0.6&lE;W(nâˆ’1)/&lgr;&lE;1.0 where W indicates the depth of the relief function, n denotes a refractive index of a lens material, and &lgr; represents a wavelength of the semiconductor laser.