Compact double-pass wavelength multiplexer-demultiplexer

A monolithically formed optical multiplexing and demultiplexing device, comprising:

• a body having a chamber formed therein, said chamber having walls;
• a fiber mounting assembly for securing a plurality of optical fibers, said fiber mounting assembly being fixed within a port formed through said walls of said chamber;
• a first reflecting surface for collimating and focusing one or more beams from said plurality of optical fibers, said first reflecting surface being formed on a first wall of said chamber;
• a transmissive grating including a diffractive element formed from a photosensitive medium, said transmissive grating being formed within said chamber;
• and
• a second reflecting surface for receiving one or more beams reflected by said first reflecting surface and passed transmissively through said grating, and reflecting said one or more beams back transmissively through said grating and said first reflecting surface to one or more of said plurality of optical fibers, said second reflecting surface being formed on a second wall of said chamber, wherein said grating is disposed at a distance from said second reflecting surface, said distance being optimized in order to substantially eliminate reflection of beams from said grating and said second reflecting surface back toward said optical fibers, wherein said second reflecting surface includes a mirror having a surface and a width, wherein said grating has a width and is disposed at a predetermined orientation angle relative to said first reflecting surface, wherein said first reflecting surface has an effective diameter, and wherein said distance is measured between a center point of said grating and said surface of said mirror, said distance being determined in accordance with a relationship expressed as,
• d≧0.5*{(D+M)/tan(2α)+D tan α},
• wherein d represents said distance, M represents said width of said mirror, α represents said grating orientation angle, and D represents said effective diameter of said first reflecting surface.

An optical multiplexing and demultiplexing device, comprising:

• a fiber mounting assembly for securing a plurality of optical fibers, each terminating in a fiber end for radiating and receiving associated light beams;
• reflecting means for reflecting beams radiating from said fiber ends;
• a collimating and focusing lens for collimating and focusing beams propagating between said fiber ends and said reflecting means;
• and
• a transmissive grating for diffracting beams propagating between said lens and said reflecting means, said grating including a diffractive element formed from a photosensitive medium, and being disposed at a first distance from said lens, wherein said first distance is optimized in order to substantially eliminate reflection of beams incident on said grating back toward said optical fibers, wherein said grating is disposed at a second distance from said reflecting means, wherein said grating has a width and is disposed at a predetermined orientation angle relative to said lens, wherein said lens has an effective diameter, said second distance also being optimized in order to substantially eliminate reflection of beams from said grating and said reflecting means back toward said optical fibers, wherein said reflecting means includes a mirror having a surface and a width, and wherein second distance is measured between a center point of said grating and said surface of said mirror, said second distance being determined in accordance with a relationship expressed as,
• d≧0.5*{(D+M)/tan(2α)+D tan α},
• wherein d represents said second distance, M represents said width of said mirror, α represents said grating orientation angle, and D represents said effective diameter of said lens.

An optical multiplexing and demultiplexing device, comprising:

• a fiber mounting assembly for securing a plurality of optical fibers, each terminating in a fiber end for radiating and receiving associated light beams;
• reflecting means for reflecting beams radiating from said fiber ends;
• a collimating and focusing lens for collimating and focusing beams propagating between said fiber ends and said reflecting means;
• and
• a transmissive grating for diffracting beams propagating between said lens and said reflecting means, said grating including a diffractive element formed from a photosensitive medium, and being disposed at a first distance from said lens, wherein said first distance is optimized in order to substantially eliminate reflection of beams incident on said grating back toward said optical fibers, wherein said grating is disposed at a second distance from said reflecting means, wherein said grating has a width and is disposed at a predetermined orientation angle relative to said lens, wherein said lens has an effective diameter, said second distance also being optimized in order to substantially eliminate reflection of beams from said grating and said reflecting means back toward said optical fibers, wherein said reflecting means includes a convex shaped mirror having a surface and a width, and wherein said second distance is measured between a center point of said grating and a center point of said surface of said convex shaped mirror, said second distance being determined in accordance with a relationship expressed as,
• d≧0.5*{(D+M)/tan(2α)+D tan α},
• wherein d represents said second distance, M represents said width of said mirror, α represents said grating orientation angle, and D represents said effective diameter of said lens.