Patent ID: 6640025
Filing Date: 2003-10-28
Classification: G02B

Abstract:
An optical apparatus for use in bidirectional optical communication comprising:a common terminal used to receive diverging light with a long wavelength and to output light with a wavelength which is shorter than the long wavelength; an input terminal used to receive diverging light with the short wavelength from a light source; an output terminal used to send out light with the long wavelength to a light receiver; a wavelength selecting filter adapted to cause said light with the long wavelength transmitted from said common terminal to pass toward said light receiver and to reflect said light with the short wavelength transmitted from said input terminal to selectively direct said light to said common terminal; and first and second computer-generated holograms used to guide said diverging light with the short wavelength transmitted from said input terminal to said common terminal via said wavelength selecting filter and to cause said light with the short wavelength to converge to said common terminal, said second computer-generated hologram additionally causing said diverging light with the long wavelength transmitted from said common terminal to converge to said light receiver, wherein said light receiver is located on one side of said wavelength selecting filter, and said common terminal, said input terminal for said light source, and said first and second computer-generated holograms are located on the other side of said wavelength selecting filter.