Signal beam

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

Quasistable bright dissipative holographic solitons in photorefractive two-wave mixing system

Abstract: The dynamical evolution of both signal and pump beams are traced by numerically solving the coupled-wave equation for a photorefractive two-wave mixing system. The direct simulations show that, when the intensity ratio of the pump beam to the signal beam is large enough, the pump beam presents a common decaying behaviour without modulational instability (MI), while the signal beam can evolve into a quasistable spatial soliton within a regime in which the pump beam is depleted slightly. The larger the ratio is, the longer the regime is. Such quasistable solitons can overcome the initial perturbations and numerical noises in the course of propagation, perform several cycles of slow oscillation in intensity and width, and persist over tens of diffraction lengths. From physical viewpoints, these solitons actually exist as completely rigorous physical objects. If the ratio is quite small, the pump beam is apt to show MI, during which the signal beam experiences strong expansion and shrinking in width and a drastic oscillation in intensity, or completely breaks up. The simulations using actual experimental parameters demonstrate that the observation of an effectively stable soliton is quite possible in the proposed system.

Demonstration of demultiplexing with a rocking filter fiber

Abstract: We show that the presence of a strong pump beam detuned from the center wavelength of a rocking filter fiber causes a signal beam at the filter resonance frequency to switch between polarization states. This process is used to switch out a pulse from a pulse train.

Theory of intracavity-pumped photorefractive phase-conjugate mirror

Abstract: We present a new type of phase-conjugate mirror that is based on an externally driven Fabry-Perot interferometer with intracavity-pumped photorefractive material, which is probed by the signal beam. It is shown theoretically that such a configuration leads to multivalued solutions and possibly to bistability. This configuration also permits optical control of the resonator output and electrical control of the phase-conjugate reflectivity.

Mechanical optical switch

Abstract: The utility model discloses a single-end mechanical optical switch, comprising a multi-optical fiber collimator, a fixed reflector and an active reflector; wherein, the multi-optical fiber collimator comprises N (N is more than or equal to 1) ports for inputting signal beam and M (M is more than or equal to 2) ports for outputting signal beam; the fixed reflector is composed by a multilateral prism plated with a piece of reflective film; the active reflector is driven by a driving device with a relay The utility model can realize signal-ended N*M light path conversion as the input and the output are fixed in a multi-optical fiber collimator, and has the advantages of simple structure, few elements and low cost

Correlation-Based Multiplexing of Complex Amplitude Data Pages in a Holographic Storage System Using Digital Holographic Techniques

Abstract: Holographic recording media can store the amplitude and the phase, or the complex amplitude, of a beam on the basis of holography. Owing to this characteristic, digital data can be encoded onto the complex amplitude of a signal beam in holographic data storage. However, most of conventional holographic storage systems encode digital data onto the amplitude alone because there are difficulties for modulating and detecting the phase. To solve the difficulties, a holographic storage system using digital holographic techniques has been proposed. With the help of digital holographic techniques, it is possible to modulate and detect the complex amplitude of a signal beam. Moreover, the proposed system can modulate the complex amplitude of a reference beam. In this paper, by making use of the capability, a correlation-based multiplexing with uncorrelated reference beams is demonstrated in the proposed system. Multiple holograms can be recorded in the same volume of a recording medium with no need for mechanical movements. Experimental results show that the proposed system with a correlation-based multiplexing can improve the storage capacity and can utilize the full potential of a recording medium without crosstalk noise stem from the optical setup.