Wideband radio frequency spectrum analyzer: improved design and experimental results

We report on significant progress accomplished in spectral-hole-burning-based instantaneous spectral analysis of optically carried broadband radio frequency signals. This concept aims at becoming the next generation spectrum analyzer for broadband radar and astronomical applications. Since the initial demonstration (Opt. Lett. 26 (2001) 1245) the spectral range has been broadened by two orders of magnitude and the channel number has been improved by nearly one order of magnitude. We discuss the next steps to be considered, namely 100% duty cycle and 1000-channel operation. On the way to 100% duty cycle operation, we demonstrate frequency offset-locking of a frequency-chirped laser to a fixed frequency laser. We examine two-dimensional angular addressing as a technique to increase the spectral channel number.