Simultaneous fiber-optic transport and RF phase control of narrow-band millimeter-wave signals using multicontact monolithic semiconductor lasers

We demonstrate fiber-optic transport over 2.2 km of single-mode fiber with continuous RF phase control of narrow-band millimeter-wave signals using a three-section monolithic distributed Bragg reflector (DBR) laser. By injection-locking the laser at the cavity round-trip resonant frequency of 45 GHz, we achieve 360/spl deg/ of continuous, linear RF phase control of the input mm-wave signal by simply varying the bias current into the laser. The RF phase shift of the 45 GHz tone versus bias current into the phase section of the laser is characterized in detail. Carrier-to-noise and locking bandwidth measurements are performed. Dynamic RF phase control of the mm-wave optical transmitter is also demonstrated by modulating the bias current into the phase section of the device, resulting in an RF phase modulated 45 GHz subcarrier with good AM suppression.