Tunable single-frequency cascaded Stokes order generation in monolithic diamond Raman resonators

We demonstrate the production and precise tuning of widely spaced (40 THz) frequency-stabilized Fourier-limited pulses produced by a cascaded Raman process in a 7-mm long integrated diamond Fabry-Perot resonator operating in the visible spectral range. The device was capable of simultaneously generating single axial Stokes modes with linewidths of <i>Δ</i><i>ν</i>_<i>S</i>1= 300 ± 35 MHz at <i>λ</i>_<i>S</i>1= 573 nm, and <i>Δ</i><i>ν</i>_<i>S</i>2= 180 ± 50 MHz at <i>λ</i>_<i>S</i>2= 623 nm, from a pump at <i>λ</i>_<i>P</i>= 532 nm. The tuning was achieved by adjusting the resonator temperature, providing over 20 GHz and 40 GHz of tuning range for the first and second Stokes orders, respectively. In this configuration, the 2nd Stokes center-frequency fluctuations were less than 50 MHz (RMS), while its linewidth was in the range of 180-400 MHz across the entire tuning range.