Bending of Light to Enhance Wavelength Conversion

Anonymous

Keisuke Kondo, Toshihiko Baba

Dynamic wavelength conversion (DWC) is obtained by controlling copropagating slow-light signal and control pulse trajectories. Our method is based on the understanding that conventional resonator-based DWC can be generalized, and is linked to cross-phase modulation. Dispersion-engineered Si photonic crystal waveguides produce such slow-light pulses. Free carriers generated by two-photon absorption of the control pulse dynamically shift the signal wavelength. Matching the group velocities of the two pulses enhances the shift, elongating the interaction length. We demonstrate an extremely large wavelength shift in DWC (4.9 nm blueshift) for the signal wavelength. Although DWC is similar to the Doppler effect, we highlight their essential differences.

Philippe Lalanne

Chang‐Qing Xu, John Bracken, Bo Chen

Intracavity sum-frequency generation and cascaded χ(2) wavelength conversions in a fiber ring resonator using a MgO-doped LiNbO3 quasi-phase-matched waveguide and an erbium-doped fiber amplifier were proposed and demonstrated. In the proposed configuration, the resonator enhances the pump light, and efficient wavelength conversion is realized. Dependence of converted signal power upon the position of a coupler used to couple a signal into the resonator and upon the round-trip loss of the resonator was studied in detail. The proposed configuration provides efficient wavelength conversion over a wide range of input signal power and resonator round-trip loss. The configuration provides a cost-effective solution to enhance pump power, thus increasing wavelength-conversion efficiency for practical system applications.

Joseph A. Giordmaine

Jerry A. Gelbwachs, Yat C. Chan

We have demonstrated 25% internal photon conversion efficiency of a new passive atomic filter. The signal wavelength matches an intense Fraunhofer line at 422.7 nm, thereby offering enhanced sunlight rejection. A quasimolecular interaction promotes rapid energy transfer between the 4p (1)P(1) level and the 4p (3)P(J) level of neutral calcium for wavelength shifting of 422.7-nm light into 657.3-nm emission. We discuss augmentation of the photon conversion efficiency by radiation trapping.