Electro-absorption modulated laser with integrated filter layer
AssigneeApplied Optoelectronics, Inc.
InventorsDapeng XU, Jin HUANG, Huanlin ZHANG
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Abstract
The present disclosure is generally directed to an EML with a filter layer disposed between an active region of the EML and a substrate of the EML to absorb a portion of unmodulated light energy, and preferably the unmodulated light energy caused by transverse electric (TE) substrate mode. The filter layer preferably comprises a material with an energy band gap (Eg) that is less than the energy band gap of the predetermined channel wavelength to absorb unmodulated laser light.
Claims18
An electro-absorption modulated laser (EML) to emit a predetermined channel wavelength, the EML comprising:
- a substrate;
- a distributed feedback (DFB) section provided by a first plurality of layers disposed on the substrate;
- an electro-absorption modulator (EAM) section provided by a second plurality of layers disposed on the substrate;
- an active region provided by the DFB section and the EAM section;
- a filter layer disposed between the substrate and the active region, the filter layer comprising a material with an energy band gap less than an energy bandgap of the predetermined channel wavelength.
A transmitter optical subassembly (TOSA) comprising:
- an electro-absorption modulated laser (EML) to emit a predetermined channel wavelength, the EML comprising a plurality of layers disposed on a substrate to provide an active region, and wherein the EML includes a filter layer disposed between the substrate and the active region, the filter layer comprising a material with an energy band gap that is less than the energy band gap of the predetermined channel wavelength.
Dependencies are inferred from the claim text.