HCG MEMS tunable VCSEL with intracavity integrated detector

We report the design and manufacturing of a tunable VCSEL with an HCG MEMS mirror and an integrated detector oblique to the optical cavity for measuring output power without disturbing the laser cavity. This allows for a single laser device with integrated power monitoring capabilities that can be used in concert with external electronics to stabilize the power or monitor optical feedback of the device for sensing applications. The HCG tunable VCSEL is modified to incorporate a sacrificial layer capable of detecting light at the VCSEL’s operating wavelength. For the MEMS release process, the sacrificial layer is removed from the optical cavity defined by the VCSEL mirrors and active region. The release process is designed to create a cavern around the optical cavity and walls of such cavern are composed by sacrificial layer material. Thus, the sacrificial layer material is removed from the optical cavity, but is kept surrounding it. Light scattered at the interface semiconductor-air hits the cavern walls and modifies current through the MEMS terminals (I_det). Any change in VCSEL output power (P_out) is directly related to a change on I_det through MEMS terminal, creating a direct relationship of P_out vs. I_det. To the best of our knowledge, there is no previous report of a VCSEL with integrated oblique intracavity detector.