부산대학교 도서관

We report on the generation and tuning of single-frequency laser light in a monolithic Fabry–Pérot diamond Raman resonator operating in the visible spectral range. The device was capable of squeezing the linewidth of a broad multi-mode nanosecond pump laser (Δ ν p = 7.2 ± 0.9 GHz at λ p = 450 nm) to a nearly Fourier-limited single axial mode Stokes pulse (Δ ν S = 114 ± 20 MHz at λ S = 479 nm). The tuning was achieved by precise adjustment of the resonator temperature, with a measured frequency-temperature tuning slope of ∂ ν 0 / ∂ T ≈ −3 GHz/K, and a temperature dependence of the first-order Raman phonon line of ∂ ν R / ∂ T ≈ +0.23 GHz/K. The Stokes center frequency was tuned continuously for over 20 GHz (more than twice the free spectral range of the resonator), which, in combination with the broad Ti:Sapphire laser spectral tunability, enables the production of Fourier-limited pulses in the 400–500 nm spectral range. The Stokes center-frequency fluctuations were 52 MHz (RMS) when the temperature of the resonator was actively stabilized. Moreover, the conversion efficiency was up to 30%, yielding an overall power spectral density enhancement of > 25 × from pump to Stokes pulse. [ABSTRACT FROM AUTHOR]