Signal beam

About: Signal beam is a research topic. Over the lifetime, 1881 publications have been published within this topic receiving 20717 citations.

Optical fiber communication system using optical phase conjugation as well as apparatus applicable to the system and method of producing the same

Abstract: An optical fiber communication system according to the present invention has, for example, first and second phase conjugators. The first phase conjugator converts a signal beam from a first optical fiber into a first phase conjugate beam. The first phase conjugate beam is supplied to the second phase conjugator by a second optical fiber. The second phase conjugator converts the first phase conjugate beam into a second phase conjugate beam. The second phase conjugate beam is transmitted by a third optical fiber. The second optical fiber is composed of a first portion located between the first phase conjugator and a system midpoint and a second portion located between the system midpoint and the second phase conjugator. The total dispersion of the first optical fiber substantially coincides with the total dispersion of the first portion, and the total dispersion of the second portion substantially coincides with the total dispersion of the third optical fiber. By the construction, waveform distortion by chromatic dispersion or nonlinearity is compensated for.

Three-color coherent light system

Abstract: A three-color coherent light system includes a laser source for generating a laser beam in the 1000-1100 nm wavelength region; means, responsive to the laser source, for generating the second harmonic of the laser beam; an optical parametric oscillator for providing a signal beam and an idler beam; means for splitting the second harmonic of the laser beam into a first beam for providing a source of coherent green light and a second beam for pumping the optical parametric oscillator to produce the signal and idler beams; means for generating the second harmonic of the signal beam as a source of coherent blue light; and means for generating the second harmonic of the idler beam as a source of coherent red light.

Externally pumped high repetition rate femtosecond infrared optical parametric oscillator

Abstract: The first externally pumped high repetition rate optical parametric oscillator (OPO) which produces tunable femtosecond pulses in the near‐infrared is demonstrated. The singly resonant oscillator with a KTiOPO4 (KTP) nonlinear crystal is synchronously pumped by 150‐fs pulses at 645 nm from a mode‐locked dye laser. With a pump power of 280 mW, stable 220‐fs pulses at a 76‐MHz repetition rate, tunable from 1.20 to 1.34 μm with a single set of mirrors, are achieved. The internal power conversion efficiency is 13% and the average infrared power is as large as 30 mW, for the signal beam only. Femtosecond pulses tunable over the wavelength range from 0.9–4.5 μm (with KTP) using multiple mirror sets should be possible. This range includes the technologically important regime from 1.0–1.6 μm.

Method and apparatus for phase correlation holographic drive

Abstract: A holographic storage apparatus for recording data in a holographic medium includes at least one light source for generating a reference beam and a signal beam. The reference beam is preferably a phase beam of unchanging phase content. The apparatus also includes a holographic medium placed in a path of the reference beam and a path of the signal beam. The holographic medium has a first face and both the reference beam and the signal beam enter the holographic medium through the first face. The holographic medium also includes a data reflective surface. The reference beam and the signal beam interfere in the holographic medium to create a hologram only after at least one of the reference beam and the signal beam have reflected off of the data reflective surface.

Theory of lossless polarization attraction in telecommunication fibers

Abstract: In this work, polarization attraction is meant to be the conservative nonlinear effect that transforms any arbitrary input state of polarization (SOP) of an intense optical signal beam fed to a nonlinear medium into approximately one and the same SOP at the output, provided that the medium is driven by a relatively stronger counterpropagating pump beam. Essentially, the combination of the nonlinear medium and the pump beam serves as a lossless polarizer for the signal beam. The degree of polarization of the outcoming signal beam can be close to 100% (90% in our present simulations). With an eye toward the development of such lossless polarizers for fiber optics applications, we theoretically study the polarization attraction effect in the optical fibers that are used in telecommunication links; i.e., randomly birefringent fibers. A generic model for the fiber-based lossless polarizers is derived, and a statistical scheme for the quantification of their performance is proposed.