High thermal conductivity vertical cavity surface emitting laser (VCSEL)
View Patent ↗A light generating device such as a VCSEL includes a light generation layer, a top reflector, a bottom reflector, and a high thermal conductivity (HTC) layer between the light generation layer and the bottom reflector. The light generation layer is adapted to generate light having a first wavelength. Heat produced at the light generation layer is more efficiently dissipated due to the presence of the HTC layer. Alternatively, a light generating device such as a VCSEL includes a light generation layer, a top reflector, and a high thermal conductivity (HTC) bottom reflector. Heat produced at the light generation layer is more efficiently dissipated due to the fact that the bottom reflector is a HTC DBR reflector having lower thermal resistivity than a conventional DBR reflector.
1. A vertical cavity surface emitting laser (VCSEL), comprising:
a light generation layer configured to generate light having a known wavelength;
a reflector;
at least one high thermal conductivity (HTC) layer disposed between the light generation layer and the reflector, the HTC layer having a thickness defined by an integer multiple of one-half the known wavelength, the HTC layer in consequence being substantially optically transparent to the generated light and having optical properties independent of the refractive indices of other layers in contact therewith, the HTC layer having a thermal conductivity exceeding that of the reflector, the HTC layer further being configured to remove and dissipate heat generated by the light generation layer.
2. The VCSEL of claim 1 wherein said reflector is a distributed Bragg reflector (DBR).
3. The VCSEL of claim 1 wherein said at least one HTC layer comprises an element selected from a group consisting of Aluminum Arsenide, Gallium Arsenide, and Indium phospide.
4. The VCSEL of claim 1 further comprising an electrode connected to said reflector.
5. The VCSEL of claim 1 further comprising a contact layer configured adapted to provide electronic contact between an electrode and said light generation layer.
6. The VCSEL of claim 5 further comprising an etch stop layer in connection with said contact layer.
7. The VCSEL of claim 1 , wherein the thickness of the at least one HTC layer is one-half the known wavelength.
8. The VCSEL of claim 1 , wherein the at least one HTC layer is further configured as a current spreading layer.
9. The VCSEL of claim 1 , wherein the at least one HTC layer is incorporated into the reflector, the HTC layer and the reflector together forming an HTC reflector.
10. The VCSEL of claim 1 , wherein at least one of an etch stop layer and a contact layer is disposed between the light generation layer and the at least one HTC layer.