Fidelity Of Phase Conjugation Research Articles

Interferometric fidelity of self-pumped phase conjugation in BaTiO 3 and a four-wave mixing set-up with Bi 12 SiO 20 using nanosecond pulses

Interferometric fidelity of self-pumped phase conjugation in BaTiO 3 and a four-wave mixing set-up with Bi 12 SiO 20 using nanosecond pulses

Interferometric fidelity of self-pumped phase conjugation in BaTiO3 and a four-wave mixing set-up with Bi12SiO20 using nanosecond pulses

The fidelity of a self-pumped phase conjugating mirror (SPPCM) in the so-called cat configuration is studied with an interferometric method for a cobalt-doped barium titanate crystal (BaTiO3:Co) under pulse illumination (8 ns, 532 nm). With this SPPCM a phase conjugating four-wave mixing set-up using the sillenite-type crystal Bi12SiO20 (BSO) was realized. It is shown that the fidelity of both phase conjugating processes under pulse illumination nearly reaches the fidelity of continuous-wave experiments.

Photorefractive Materials and Their Applications. High-Power Nd:YAG laser Using Ring Self-Pumped Phase Conjugate Mirror.

A LD-pumped sigzag slab Nd:YAG oscillator-amplifier system using a photorefractive ring self-pumped phase conjugate mirror is developed. The photorefractive phase conjugator is optimized in the point view of high-energy pulse capacity, fidelity of phase conjugation and stability. The laser system generates the IR laser pulses of 600 mJ and the second harmonic pulses of 250 mJ at the repetition rate of 100 Hz. Both the IR and the second harmonic have 1.1 times diffraction limited beam quality.

Phase conjugation of a speckle-inhomogeneous beam by an Nd glass oscillator based on four-wave mixing with feedback

A study is reported of a system, making use of four-wave mixing with feedback (FWMF), for high-quality phase conjugation of speckle-inhomogeneous radiation. The system includes a hologram formed on the basis of nonlinearity of gain saturation. A theoretical analysis is made of selective capabilities of a 'short' hologram, whose length is less than the longitudinal correlation lengths of the 'write' waves used to form it. The statistical-average values of the parameters of modes in an FWMF cavity are determined. The experimental results obtained for a neodymium glass system show that the fidelity of phase conjugation of speckle beams with a divergence (5 — 25) θdiffr is 80%. The maximum energy of the phase-conjugated component is 0.35 J and the maximum energy reflection coefficient of an FWMF mirror is 20.

Fidelity of phase-conjugated beams in a four-wave mixing set-up using Bi12TiO20-crystals

Abstract The quality of the aberration compensation provided by phaseconjugating mirrors (PCMs) is important for applications in lensless imaging or interferometry. In many cases an accuracy of a tenth of the wavelength for the phase reversal is sufficient. It will be shown that both the Fourier fringe evaluation method and a lensless image projection technique are useful to characterize the fidelity of phase conjugation with BaTiO3. A quantitative evaluation of the fidelity is given for four-wave mixing in Bi12TiO20 and selfpumped PCM with BaTiO3.

?(3) scattering noises in nonlinear optical phase conjugation

Phase conjugation by Four-Wave Mixing (FWM) is treated quantum mechanically as a multiphoton scattering process. The spontaneous scattering of two counter-propagating photons gives rise to a background noise, whereas the stimulated scattering in the presence of the probe beam generates the phase conjugate signal. In addition, the stimulated scattering also contributes to a background noise which has never been discussed. Compared with Rayleigh scattering noise, the χ(3) scattering noises are relatively small for intensity up to 108 W/cm2. For higher intensities, the χ(3) scattering noises, in conjunction with the Rayleigh scattering noise, will affect the spatial fidelity of the optical phase conjugation.

BaTiO_3 waveguide self-pumped phase conjugator

For the first time to our knowledge, self-pumped phase conjugation is reported in a planar waveguide structure in a BaTiO3 single crystal. The waveguide was fabricated by the technique of ion implantation, with 1.5-MeV H+ ions at a dose of 1016 ions/cm2. Phase-conjugate reflectivities >20% have been measured for waveguide self-pumped phase conjugation, and, for a given input power, an order-of-magnitude reduction in the response time is observed in the waveguide compared with the bulk. The fidelity of phase conjugation in the guide is also discussed.

Hermite-gaussian theory of focused beam SBS cells

The reflectance and fidelity of phase conjugation of stimulated Brillouin scattering (SBS) is studied in the saturation region for focusing in an unbounded medium. The electric fields are expanded into Hermite-gaussian modes. The resulting equations for the mode amplitudes are compared with those for SBS in a waveguide. Numerical calculations for reflectance and fidelity as function of pump power are presented for TEM 00 mode pumping. Shot to shot fluctuations of reflectance and fidelity are predicted as a result of Stokes wave generation from noise.

Fidelity of optical phase conjugation by photorefractive degenerate four-wave mixing in barium titanate

The fidelity of optical phase conjugation resulting from photorefractive degenerate four-wave mixing in barium titanate was investigated using an interferometric technique. The effect on the fidelity of varying the relative intensities of the beams entering the crystal was studied. It was found that the intensity of the image to be conjugated as a fraction of the total intensity in the crystal is the dominant factor. The effects of angular misalignment of the incident laser beams were investigated and a strict angular criterion established. The angular tolerance appears to be determined by the Bragg diffraction criterion for infinite plane waves, which may be much less than the divergence of the image bearing beam to be phase conjugated.

Fidelity of optical phase conjugation by degenerate four-wave mixing in semiconductor glasses and ruby

The fidelity of phase conjugation by degenerate four-wave mixing in ruby and semiconductor-doped glasses has been measured by means of our own modified Twyman–Green interferometer [Opt. Lett. 14, 183 (1989)] implementing two phase conjugate mirrors. It is shown that the fidelity of phase conjugators with an OG530 color filter as the nonlinear medium reaches a value of 99%. The fidelity of ruby is also reported. Additionally the effect of the recording system on the value of the fidelity is discussed.

Michelson interferometer with a holographic memory for measuring fidelity of aberrated phase conjugated beams

A new interferometer has been developed which combines aspects of a Michelson interferometer with the storage capabilities of holography. The instrument makes it possible to compare interferometrically beams that are not coherent with one another. The instrument was used to measure fidelity of phase conjugation by common mode rejection of aberrators.

Test of fidelity of phase conjugation

The fidelity of the phase-conjugate signal produced by degenerate four-wave mixing was evaluated by conjugating and recombining the multiple-beam output from a phase grating. A single output beam resulted. If one or more of the beams emerging from the grating were blocked, additional beams appeared whose relative amplitudes agreed with theory for a perfect phase conjugator.