Optical Mixing in Raman-Active Medium

Rostislav M. Arkhipov, A. V. Pakhomov, Ihar Babushkin +3 more

We study theoretically a new possibility of unipolar pulse generation in a Raman-active medium excited by a series of few-cycle optical pulses. We consider the case when the Raman-active particles are uniformly distributed along a circle or helix, and demonstrate the possibility of obtaining rectangular unipolar pulses with an arbitrarily long duration above the minimum value equal to the natural period of the low-frequency vibrations in the Raman-active medium.

M Martin

G.Ya. Lyubarskii

Govind Prasad Agrawal

This chapter focuses on the effects of loss or gain in a graded-index (GRIN) medium. In Section 6.1, we discuss the impact of losses on the modes of such a medium. Section 6.2 considers the mechanisms used for providing optical gain inside a GRIN medium. Section 6.3 is devoted to Raman amplifiers and Raman lasers, built with GRIN fibers and pumped suitably to provide optical gain. Parametric amplifiers are discussed in Section 6.4, together with the phase matching required for four-wave mixing to occur. The focus of Section 6.5 is on amplifiers and lasers made by doping a GRIN fiber with rare-earth ions. Section 6.6 includes the nonlinear effects and describes the formation of spatial solitons and similaritons inside an active GRIN medium.

Kaijun Jiang, L. Deng, M. G. Payne

Using a single-channel active Raman gain medium, we show a $220\ifmmode\pm\else\textpm\fi{}20\phantom{\rule{0.3em}{0ex}}\mathrm{ns}$ advance time for an optical pulse of ${\ensuremath{\tau}}_{\mathit{FWHM}}=15.4\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{s}$ propagating through a $10\phantom{\rule{0.3em}{0ex}}\mathrm{cm}$ medium, a lead time that is comparable to what was reported previously using a two-mode pump field. In addition, we have verified experimentally all the features associated with this single-channel Raman gain system.

Махвиладзе Тариэль Михайлович, Сарычев Михаил Евгеньевич, Leonid A. Shelepin