1.55‐μm surface‐illuminated monolithically integrated balanced metal semiconductor metal photodetectors and coplanar waveguide

Two metal–semiconductor–metal (MSM) photodetectors are integrated monolithically with a coplanar waveguide transmission line to form a 1.55‐μm surface‐illuminated balanced photodetector. Illuminating the device with CW and taking the difference, the relative intensity noise (RIN) is suppressed by 9–10 dB. In balanced detection, a 7‐dB enhancement in the intermodulation term compared to single detector is achieved.