Signal beam

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

Electromagnetic radiation apparatus for analyzing small particles

Abstract: Method and apparatus for measuring static and dynamic properties of small particles are disclosed. A beam of energy is split into signal and reference beams. The signal beam is focused into a sample cell containing a solution or suspension of the particles to be analyzed, where it is scattered by interaction with the particles. Energy scattered at some angle is passed through restrictive apertures and a collecting lens to a detector. The reference beam is directed through an attenuator and a focusing lens to a fixed scattering matrix, which is located along the path of propagation of the scattered signal light. A portion of the scattered reference light is passed through a restrictive aperture to the detector where it is heterodyned with the scattered signal light.

Method and apparatus for ultrafast serial-to-parallel conversion and analog sampling

Abstract: When sampled simultaneously by a set of synchronized high intensity beams, a device consisting of a sequence of interlinked Nonlinear Sampling-Gates, through which a signal beam propagates, generates a replica of the intensity of the signal beam, during the interaction period. The device may be implemented optically or electrically as an ultra-high speed parallel receiver and when sampled by a femtolaser may be used to read a data train in parallel and thus at almost in real time. The device may also be used to stretch, compress, multiplex, demultiplex, read headers and help switch data trains optically in communication networks.

Generation of few-cycle infrared pulses from a degenerate dual-pump OPCPA.

Abstract: A degenerate dual-pump optical parametric chirped-pulse amplifier (OPCPA) for generation of few-cycle intense pulses centered at 1.6 μm is theoretically investigated. By adding the optimized linear chirp to the two pump pulses from Ti:sapphire source and carefully adjusting the delays between the two pumps and seed, the long- and short-wavelength components of the seed pulse are efficiently amplified during the parametric process. Our simulations show that a broadband spectrum spanning from 1.3 μm to 2.1 μm is attained with a conversion efficiency of 22.6%. Signal pulse with a near transform-limited (TL) duration of 10.1 fs can be achieved by simply removing the linear chirp from the output signal. Besides, the compressed signal beam manifests good quality both spectrally and temporally, which allows tightly focusing the signal beam for further use.

Signal stabilization in optical hydrophones

Abstract: A system for signal stabilizing in-phase modulated optical hydrophone arr employs interferometry with homodyne detection. Phase stabilization is accomplished by modulating the input laser signal in proportion to variations in the output of an optical transducer to balance the output phase so that the fringes are kept at optimum position. Additionally, fluctuations in light intensity are compensated for so that a photodetector responds only to phase shift variations. The technique used is to split the input beam into signal and reference beams using a beam divider, exposing the signal beam to the acoustic pressure of interest, recombining the signal beam with the reference beam, detecting the combined beams and filtering the resulting signal to separate out the acoustic information of interest from the phase shift and light intensity portions used to stabilize the input beam. The acoustic information is processed and the phase shift and light intensity information provides a feedback signal for use in input beam stabilization.

Self-referential holography and its applications to data storage and phase-to-intensity conversion

Abstract: Holographic recording methods require the use of a reference beam that is coherent with the signal beam carrying the information to be recorded. In this paper, we propose self-referential holography (SRH) for holographic recording without the use of a reference beam. SRH can realize purely one-beam holographic recording by considering the signal beam itself as the reference beam. The readout process in SRH is based on energy transfer by inter-pixel interference in holographic diffraction, which depends on the spatial phase difference between the recorded phase and the readout phase. The phase-modulated recorded signal is converted into an intensity-modulated beam that can be easily detected using a conventional image sensor. SRH can be used effectively for holographic data storage and phase-to-intensity conversion.