High Frequency Modulation of Transverse-Coupled-Cavity VCSELs for Radio Over Fiber Applications

We demonstrate a high-speed and efficient direct modulation of a novel transverse-coupled-cavity vertical cavity surface emitting laser for radio over fiber applications. A bow-tie joint connection between two oxide apertures results in a leaky traveling wave in the lateral direction between the two cavities. The measured L/I characteristics and lasing spectra demonstrate coherent coupling of the two cavities. The small signal response of the fabricated device shows a large enhancement of over 30 dB in the modulation amplitude at frequencies . The resonantly enhanced modulation response is suitable for efficient narrow-band modulation in the millimeter wave range over 25 GHz far beyond the intrinsic modulation bandwidth of the laser without optical feedback.