A method for manufacturing a distributed Bragg reflector. The distributed Bragg reflector is applied to a 1550 nm vertical-cavity surface-emitting laser, which structurally includes a top distributed Bragg reflector, a bottom distributed Bragg reflector, and a vertical cavity (including a P-type and an N-type electrode) and a multiple quantum well light-emitting layer that are positioned therebetween. An optical multilayer film of the distributed Bragg reflector is formed by sputtering, and includes silicon layers and silicon dioxide layers alternately stacked to each other. The silicon dioxide layers are produced by a process of nano-sputtering and micro-plasma oxidation. A reflectance of the bottom distributed Bragg reflector at 1,550 nm is greater than 99.9%, and a reflectance of the top distributed Bragg reflector at 1,550 nm is controlled to be between 95% and 99%, so that basic physical/optical requirements for forming a resonant laser can be improved.

High bandwidth (e.g., >100 GHz) modulators and methods of fabricating such are provided. An EAM comprises a waveguide mesa comprising a continuous multi-quantum well (MQW) layer; a plurality of electrode segments disposed on the waveguide mesa; and a microstrip transmission line disposed on an insulating material layer and in electrical communication with the plurality of electrode segments via conducting bridges. The waveguide mesa comprises alternating active sections and passive sections. An electrode segment of the plurality of electrodes is disposed on a respective one of the active sections. Portions of the continuous MQW layer disposed in each of the active sections having an energy gap defining an active energy gap value. Portions of the continuous MQW layer disposed in each of the passive sections having an energy gap defining an passive energy gap value. The active energy gap value is less than the passive energy gap value.