Signal beam

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

Amplification of a stored signal beam in atomic medium with double-Λ configuration

Abstract: We study a four-level atomic system with a double-Λ configuration interacting with two probe and two control fields. The linear susceptibilities of the atomic medium show not only the dual electromagnetically induced transparency (EIT) effect, but also an amplification mechanism. The numerical simulations verify that one signal can be amplified in both the transmission and the storage processes, provided two synchronous signals are prepared as input.

Method and apparatus for detecting profile error of article surface

Abstract: An optical non-contact detection of profile errors of a surface or surfaces of an article, such as an industrial product is carried out by a coherent signal bea of light introduced along an imaginary plane and projected onto the surface of the article at a large angle of incidence. The signal beam of light is reflected from the surface toward the same imaginary plane and traveled past optical system toward a photosensitive material on which a separate reference beam of light is projected. A hologram of the surface is formed on the photosensitive material, which is used for an analysis of the profile errors of the surface.

All-optical 3R regenerator using solitary wave interactions

Abstract: A method and apparatus for all-optical signal regeneration in fiber optic communications networks is provided. The process utilizes solitary wave interactions in various nonlinear optical media to re-shape, re-amplify and re-time optical signals that have traveled over large distances of fiber-optic cable. The device consists of an optical clock generator synchronized to the system clock, recovered from the input signal by a clock recovery unit. The output of the optical clock is then used to produce a solitary wave in the nonlinear material that collides with the coincident signal beam. The net result is an all-optical signal regenerator. A multi-channel device capable of providing signal regeneration on multiple wavelengths using a single clock recovery and optical clock generator assembly is also disclosed.

Light amplification control unit and method

Abstract: A light amplification control unit whereby the gain of an optical amplifier can be controlled with ease. A plurality of pump light sources each generate a pump beam having the effect of amplifying a signal beam, and an external control light source generates an external control beam having a wavelength that influences the signal beam amplification effect by means of the pump beams. A multiplexing section multiplexes the pump beams with the external control beam and causes the multiplexed beams to enter an optical fiber in a direction opposite to that of the signal beam. A control section controls the output of the external control beam from the external control light source, whereby the gain of the signal beam amplified by the pump light sources can be controlled.

Using multiple mutually incoherent fiber lasers to pump a coherent signal beam in an optical parametric oscillator

Abstract: Although the concept of using multiple pumps to drive an optical parametric oscillator (OPO) is old, experimental evidence bearing on this possibility has been reported only recently. Periodically poled lithium niobate (PPLN) has recently been applied to the construction of efficient CW singly resonant optical parametric oscillators with a single collinear pump beam. Here we use three-dimensional numerical modeling to study the possibility of noncollinearly pumping a PPLN OPO using N CW fiber lasers. Our results suggest that a tunable signal whose power exceeds that of a single pump laser may be possible. The modeling reported here does not take thermal lensing into account, and so is appropriate for a situation where the average pump power is reduced by a mechanical chopper or where thermal effects are mitigated by a technique such as beam scanning. The modeling also assumes the availability of 40 W polarized fiber lasers operating at /spl lambda//sub p/=1.064 /spl mu/m and of 1 mm thick PPLN, whereas 20 W polarized fiber lasers and 0.5 mm thick PPLN are the current state-of-the-art. We suppose that the nonlinear grating period in the 5 cm long PPLN is chosen to quasi-phase-match signal and idler wavelengths /spl lambda//sub s/=1.5 /spl mu/m and /spl lambda//sub i/=3.66 /spl mu/m.