Phase conjugation

About: Phase conjugation is a research topic. Over the lifetime, 3694 publications have been published within this topic receiving 49099 citations.

Polarization-preserving phase conjugation and temporal reversal of an arbitrarily-polarized pulsed optical signal by means of time-and-space-domain holography

Abstract: Polarization-preserving phase conjugation of an arbitrarily-polarized multiple-pulse optical signal by using a modified scheme of time-and-space-domain holography is predicted theoretically and demonstrated experimentally. The experimental results obtained by utilizing octaethylporphin-doped polystyrene at 1.8 K as a spectrally-selective recording material indicate that in full accordance with the theory, the reconstructed phase-conjugated replicas of the multiple-pulse optical signal appear temporally reversed and have conjugated wavefronts while the original temporal and spatial dependence of the polarization state is restored. Thus, complete phase conjugation of an optical signal is demonstrated. >

An image reconstruction algorithm using phase conjugation for diffraction‐limited imaging in an inhomogeneous medium

Abstract: A diffraction‐limited imaging method in an inhomogeneous medium, which uses phase conjugation and multiple reflectors, is proposed. First, several reflectors with frequency‐dependent reflectivities are put in the observation area. Second, ultrasonic signals are acquired for all combinations of transmitter‐receiver elements of the array, and data acquisition is repeated for each of the frequencies. Then, signal processing is performed in a computer: (1) The reflected wave in the mth step is phase conjugated and transmitted to get the reflected wave in the (m+1)th step until convergence is attained; (2) the converged phase‐conjugated wave is scanned in bearing to get an image; and (3) good image parts obtained for several frequencies are joined together to extend the good image area.

Beam Combination using Stimulated Brillouin Scattering for the Ultimate High Power-Energy Laser System Operating at High Repetition Rate over 10 Hz for Laser Fusion Driver

Abstract: After the laser was invented in 1960, a phase conjugation mirror has been respected to be the most fantastic one for the laser resonator composition because it can compensate any distortions of the laser beams occurred by the many inhomogenuities of the laser media and optical components. Among the many phase conjugation configurations, the stimulated Brillouin scattering phase conjugation mirror is the most simple one and many researchers have tried to utilize it to develop high power/energy laser systems. For realizing a high energy/power laser system the thermal problem is the most difficult to solve, and some researchers suggested a beam combination technique to reduce the thermal load of the big laser media to many small sized ones. To accomplish the beam combination using stimulated Brillouin scattering phase conjugation mirrors (SBS-PCMs), it is necessary to lock/control the phases of the SBS-PCMs. And some researchers have developed several ways for it, but they can lock the phases of a limited number of beams overlapped at the foci less than 5, or lock the phases by back-seeding technique but it loses the phase conjugation characteristics. For realization of the laser fusion driver, it is necessary to combine more than 10 or 100 beams. And the authors have developed recently a new phase controlling/locking technique which is isolated and independent totally from other beams and it can be applied to an unlimited number of beams in principle.

Theoretical model for modal dispersal of polarization information and its recovery by phase conjugation

Abstract: A theoretical model is proposed for explaining the recently observed modal dispersal of polarization information and its recovery in an experiment in which the coupling dispersing fiber.