A new microwave switch, the light-activated microwave photoconductive switch consisting of a heterostructure photoconductive switch (HPCS) with a flip-chip bonded vertical-cavity surface-emitting laser is reported. An insertion loss of 0.17 dB at a laser Power of 15 mW and an isolation of 25 dB were obtained at 1 GHz. Excellent linearity was obtained with second and third order intercepts measured at 960 MHz of SOI = 115 dBm and TOI = 65 dBm at 960 MHz, respectively.