aqora

Low-noise photorefractive amplification and the detection of weak signals

Sebastien Breugnot, M. Defour, H. Rajhenbach +1 more

Conference on Lasers and Electro-OpticsMay 21, 19950 citations

Heterodyne detection of weak optical wavefronts burried in a photorefractive fanning noise

Sebastien Breugnot, M. Defour, Henri J. Rajbenbach +1 more

Optics CommunicationsDec 1, 19937 citations

Low-noise photorefractive amplification and detection of very weak signal beams

Sebastien Breugnot, Henri J. Rajbenbach, M. Defour +1 more

We present theoretical and experimental analyses of the signal-to-noise ratio (SNR) of photorefractive two-wave mixing detection that uses BaTiO(3). The influence of beam fanning is taken into account in the detection process. Different known methods to enhance the SNR of the detection are theoretically and experimentally compared. A 10-fold improvement of the SNR is obtained, and the detection of a 1-pW signal intensity for a SNR of 50 is achieved for two of them.

Optics LettersMar 1, 199513 citations

Noise reduction in photorefractive image amplifiers and applications

J.-P. Huignard, Henri J. Rajbenbach

We propose and experimentally demonstrate two original methods for suppressing the beam fanning noise of photorefractive amplifiers. The first one involves two wave mixing in a slowly rotating crystal, while the second requires to tilt the crystal with respect to the recording beams. This method applies to materials which exhibit a sharp resonance of the gain versus the pump-probe beam angle. With both methods a large improvement of the S/N ratio is achieved and virtually noise free image amplifiers are demonstrated. In Bi12SiO20, subpicowatt optical signals are detected and amplified. By using combinations of LiNbO3/Bi12SiO20, as storage and amplification crystals respectively a long term readout (more than 20 hours) of a photorefractive memory is achieved.We propose and experimentally demonstrate two original methods for suppressing the beam fanning noise of photorefractive amplifiers. The first one involves two wave mixing in a slowly rotating crystal, while the second requires to tilt the crystal with respect to the recording beams. This method applies to materials which exhibit a sharp resonance of the gain versus the pump-probe beam angle. With both methods a large improvement of the S/N ratio is achieved and virtually noise free image amplifiers are demonstrated. In Bi12SiO20, subpicowatt optical signals are detected and amplified. By using combinations of LiNbO3/Bi12SiO20, as storage and amplification crystals respectively a long term readout (more than 20 hours) of a photorefractive memory is achieved.

Journal de Physique IIIJul 1, 19930 citations

Enhancement of weak optical signal detection based on phase-sensitive amplification

Changchang Zhang, Zhaolu Wang, Wenjuan Shi +4 more

Optics & Laser TechnologyJan 17, 20252 citations

Photorefractive fourier image amplification for low-light-level image detection

G. C. Gilbreath, John F. Reintjes

In this article we demonstrate viable photorefractive image amplification in BaTiO3 at extremely low light levels. Uniform image amplification was observed over a range of intensity levels for different beam ratios. The technique is shown to be robust against beam fanning, the primary source of noise in multibeam photorefractive interactions in ferroelectric crystals. © 1996 John Wiley & Sons, Inc.

Microwave and Optical Technology LettersJun 20, 19963 citations

Photorefractive amplification and detection of weak signals buried in the beam fanning noise

Related papers

Photorefractive amplification and detection of weak signals buried in the beam fanning noise

Related papers