Super luminescent diode and manufacturing method thereof
View Patent ↗To provide a superluminescent diode capable of emitting high output super luminescent light having a central wavelength within a range of 0.95 μm to 1.2 μm and an undistorted beam cross section, having a long element life. The super luminescent diode is constituted by: an n-type GaAs substrate; an optical waveguide path constituted by an InGaAs active layer that emits light having a central wavelength within a range of 0.95 μm to 1.2 μm, formed on the GaAs substrate; and a window region layer having a greater energy gap and a smaller refractive index than the active layer, constituted by p-type GaAs that lattice matches with the GaAs substrate, provided at a rear emitting facet of the optical waveguide path. The p-type GaAs window region layer has a favorable crystal membrane with the InGaAs active layer that emits light having the central wavelength within the range of 0.95 μm to 1.2 μm, which does not deteriorate.
1. A super luminescent diode, comprising:
a GaAs substrate having a first conductivity;
an optical waveguide path constituted by an InGaAs active layer that emits light having a central wavelength within a range of 0.95 μm to 1.2 μm, formed on the GaAs substrate; and
a window region layer having a greater energy gap and a smaller refractive index than the active layer and a second conductivity different from the first conductivity, constituted by a binary or ternary semiconductor material with a lattice coefficient that lattice matches with GaAs within a range of ±0.1% and does not contain Al, provided at a rear emitting facet of the optical waveguide path.
2. An optical tomography apparatus as defined in claim 1 , wherein:
the semiconductor material of the window region later is GaAs.
3. An optical tomography apparatus as defined in claim 1 , wherein:
the semiconductor material of the window region layer is InGaP.
4. A method for manufacturing a super luminescent diode, comprising:
forming an optical waveguide path constituted by an InGaAs active layer that emits light having a central wavelength within a range of 0.95 μm to 1.2 μm, on a GaAs substrate having a fist conductivity; and
forming a window region layer having a grater energy gap and a smaller refractive index than the active layer and a second conductivity different from the first conductivity, constituted by a binary or ternary semiconductor material with a lattice coefficient that lattice matches with GaAs within a range of ±0.1% and does not contain Al, at a rear emitting facet of the optical wavelength path, wherein:
the manufacturing step following the formation of the active layer constituted by one of InGaAs and GaInNAs is performed in an environment at a temperature less than or equal to 650° C.