Direct amplitude modulation of short‐cavity GaAs lasers up to X‐band frequencies

Experimental and theoretical studies indicate that a high‐frequency laser with bandwidths up to X‐band frequencies (≳10 GHz) should be one having a short cavity with a window structure, and preferably operating at low temperatures. These designs would accomplish the task of shortening the photon lifetime, increasing the intrinsic optical gain, and increasing the internal photon density without inflicting mirror damage. A modulation bandwidth of >8 GHz has been achieved using a 120‐μm laser without any special window structure at room temperature.