title: Coherent continuous-wave dual-frequency high-Q external-cavity semiconductor laser for GHz-THz applications.
abstract: We report a continuous-wave highly-coherent and tunable dual-frequency laser emitting at two frequencies separated by 30 GHz to 3 THz, based on compact III-V diode-pumped quantum-well surface-emitting semiconductor laser technology. The concept is based on the stable simultaneous operation of two Laguerre-Gauss transverse modes in a single-axis short cavity, using an integrated sub-wavelength-thick metallic mask. Simultaneous operation is demonstrated theoretically and experimentally by recording intensity noises and beat frequency, and time-resolved optical spectra. We demonstrated a >80  mW output power, diffraction-limited beam, narrow linewidth of <300  kHz, linear polarization state (>45  dB), and low intensity noise class-A dynamics of <0.3% rms, thus opening the path to a compact low-cost coherent GHz to THz source development.
authors: Romain
authors: R
authors: Paquet
authors: Stéphane
authors: S
authors: Blin
authors: Mikhaël
authors: M
authors: Myara
authors: Luc Le
authors: LL
authors: Gratiet
authors: Mohamed
authors: M
authors: Sellahi
authors: Baptiste
authors: B
authors: Chomet
authors: Grégoire
authors: G
authors: Beaudoin
authors: Isabelle
authors: I
authors: Sagnes
authors: Arnaud
authors: A
authors: Garnache