Optical transmission module
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorSeiichiro Tabata
Life of this patent
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Abstract
An optical transmission module has a laser diode, a photodiode, a binary-type DOE lens for 1.3 μm and a DOE lens for 1.55 μm in a package. An optical fiber is arranged so that its end surface faces the optical transmission module. The laser diode radiates light of wavelength 1.3 μm. The photodiode receives light of wavelength 1.55 μm. Both DOE lenses have diffraction action of mutually different diffraction orders for light of the two wavelengths. The optical axis passing from the laser diode to the optical fiber and the optical axis passing from the photodiode to the optical fiber are separated. The optical transmission module is compact and has a small number of components.
Claims18
An optical transmission module which sends and receives light transmitted bi-directionally through an optical fiber, said optical transmission module comprising:
- a light source which radiates light of a first wavelength;
- a light-receiving section which receives light of a second wavelength emitted from said optical fiber;
- and
- a binary-type diffractive optical element with a staircase-shaped diffractive surface, which has principal diffractive action of different diffraction orders respectively for the light of said first wavelength and the light of said second wavelength, wherein
- said diffractive optical element separates the first optical axis passing from said light source to said optical fiber and the second optical axis passing from said light-receiving section to said optical fiber.
Dependencies are inferred from the claim text.