The quantum-noise properties of single-pass second-harmonic blue-light generation with femtosecond pulses have been measured. A conversion efficiency of as much as 63.5% of second-harmonic generation at 428.8 nm was observed in a KNbO<sub>3</sub> crystal with femtosecond (130-fs) pulses with wavelengths centered at 857.6 nm. The quantum noise on the generated blue light was measured to be 1.0 dB (1.4 dB of squeezing inferred) below the shot-noise limit. The noise reduction was found to be sensitive to the average power and the center wavelength of the input fundamental pulses under the condition of strong pump depletion.
© 1999 Optical Society of America
Yong-qing Li, Dorel Guzun, and Min Xiao, "Quantum-noise measurements in high-efficiency single-pass second-harmonic generation with femtosecond pulses," Opt. Lett. 24, 987-989 (1999)