Phase Conjugate Optics (With 3 Figures)

M. Blaauboer, Daan Lenstra, A. Lodder

Ruwan U. Weerasuriya, Rasmus Larsson, Peter A. Andrekson

Optical phase-sensitive amplifiers (PSAs) leverage nonlinear interactions to achieve noise figures below the conventional quantum limit. Dual-pump phase-insensitive amplification has been studied in wavelength conversion, phase conjugation and spectral inversion, but phase-sensitive amplification remains challenging due to stimulated Brillouin scattering (SBS) in optical fibers. While pump-phase modulation helps mitigate SBS, it broadens the idler spectrum, complicating practical implementation. We demonstrate a counter-phase pump modulation approach to suppress idler spectral broadening using optical coherent combining and delayed self-heterodyne techniques to achieve excellent noise figure (NF) performance in dual-pump PSAs. Our methods achieve over 30 dB suppression of residual phase modulation tones and significantly improve the idler spectrum. We obtained a 20 dB gain with an NF of 1.45 dB and a minimal NF penalty of 0.2 dB due to pump-phase modulation. This achievement enables PSAs to support optical communication, wavelength conversion, and deep-space communication applications.

J. Auyeung, Avigail Yariv

Chris Oneill, A. Blouin, F. Chenard +2 more

The temporal evolution of optical nonlinearities is an important element in the choice of materials suitable for applications such as optical switches, real-time optical correlators, and optical memories. In this paper, we report a study of the nonlinear optical properties of a (1) saturable absorber (rhodamine 6G) in solution (water and methanol) and also embedded in a polyvinyl alcohol matrix and (2) a thin film of glass doped with CdSxSe1-x microcrystallites. The temporal response of the phase-conjugate signal obtained by degenerate four-wave mixing, as well as the dynamic of higher-order resonant signals have been investigated by means of a frequency-doubled picosecond Nd:YAG laser. Intensity-dependent relaxation times have been found for some materials. Merit figures (defined as the ratio between the nonlinear susceptibility and its relaxation time) of these media have been considered for different polarization configurations. Physical mechanisms involved in the grating relaxation for these different media will be discussed.

Jun-ichi Sakai

X. Xia, D. S. Hsiung, Timothy T. Grove +1 more

Optical phase conjugation (OPC) is of interest for many applications such as optical resonators, high speed turbulence correction, and the production of the squeezed vacuum state. In the interest of practical implementation of OPC, the simplest method is to produce a phase conjugate mirror (PCM). In the work we have used the PCM as well as the gain associated with the OPC to form a ring laser.