Multiple Channel Rotary Optical Coupler

A rotating optical coupler for coupling optical signals from a first set of rotating optical conductors to a second set of stationary optical conductors includes a plurality of annular lenses, each of which is optically associated with one of the optical conductors of the first set. The lenses are nested one inside another to form a lens assembly oriented in a plane perpendicular to optical axes of the lenses. A rotating holder supports each of the conductors of the first set in parallel orientation with respect to an optical axis of a central one of the annular lenses with each conductor being positioned at a different radial distance from the optical axis of the central lens. Ends of the conductors are positioned to direct light rays at a corresponding one of the annular lenses. A second stationary holder supports ends of each of the conductors of the second set at a focal point of a respective one of the annular lenses. The second holder is coupled to the lens assembly for maintain

Optical signal coupling apparatus

An optical coupler is provided which includes a transmitter optical cable which is machined along its length to have a substantially flat, smooth lower surface. The transmitter optical cable includes a curved upper surface on which a cladding layer is situated for containing an optical signal which is provided to an input end of the transmitter optical cable. A receiver optical cable is similarly machined to include a substantially flat, smooth upper surface and a curved lower surface on which a cladding layer is situated. The flat lower surface of the transmitter optical cable and the flat upper surface of the receiver optical cable are oriented in generally parallel, spaced apart relationship with an index matching member being situated therebetween. An incident optical signal enters the input end of the transmitter optical cable, exits the lower surface thereof, enters the index matching member and the upper surface of the receiver optical cable, and exits the output end thereof. I

Heroes Are Born Then Made

Heroes Are Born Then Made is a theatre piece involving live actors on stage, and live music originating from an orchestra pit. The script and music is original. The music is meant to literally depict actions and emotions on stage whether the actors are present or not. The duration of the entire production is about two and one-half hours long. Six main actors are used with additional walk-ons. Sixteen musicians are required to make up the orchestra which is organized into a woodwind quartet, a brass trio, a string quartet, a piano, and a percussion quartet. The play is based on the author's conception of how people tend to treat each other when someone is caught at a disadvantage. Specifically it is a depiction of the conflict involved when the minor characters discover that the main character is trying to do something quite different from their definition of "normal.

Alignment procedure for a dual grating pulse compressor

Grating pulse compressors are an integral part of chirped pulse amplification (CPA) lasers.1 Accurate alignment of the compressor is required to obtain minimum pulsewidth at the output of the system. Dual grating compressors are difficult to align because they don’t function unless they are close to optimum alignment. The procedure outlined here provides a simple step-wise method of aligning a dual grating pulse compressor so that the gratings will be parallel with one another. Once this condition has been established, only the distance between the gratings needs to be adjusted to start the system operating. At this point, the compressor can be critically aligned. © 1998 Optical Society of America

Alignment procedure for a dual grating pulse compressor

Grating pulse compressors are an integral part of chirped pulse amplification (CPA) lasers.1 Accurate alignment of the compressor is required to obtain minimum pulse-width at the output of the system. Dual grating compressors are difficult to align because they don\u27t function unless they are close to optimum alignment. The procedure outlined here provides a simple step-wise method of aligning a dual grating pulse compressor so that the gratings will be parallel with one another. Once this condition has been established, only the distance between the gratings needs to be adjusted to start the system operating. At this point, the compressor can be critically aligned

Multiterawatt Femtosecond Cr:Lisaf Laser

A multiterawatt femtosecond Cr:LiSAF laser system is developed with a final amplifier aperture of 25 mm using chirped pulse amplification. The laser system uses a Kerr-lens mode-locked Ti:sapphire laser, a pulse stretcher, a regenerative amplifier followed by three additional double bass amplifiers with increasing aperture up to 25 mm and a pulse compressor. Design and performance are described in details

Multiterawatt femtosecond Cr:LiSAF laser

Cr:LiSAF has become an attractive alternative gain medium for the high intensity amplification of femtosecond optical pulses. It uniquely combines the advantages of Ti:sapphire and Nd:glass, materials commonly used as gain media in laser systems based on chirped pulse amplification. Cr:LiSAF has a broad spectral emission bandwidth similar to that of Ti:sapphire allowing the amplification of femtosecond optical pulses. In addition it has an upperstate lifetime of 67 μs long enough for efficient flashlamp-pumping leading to compact laboratory sized low-cost amplifiers using a mature technology developed over many years. Based on our investigations of the optical gain, nonlinear and optical damage properties of Cr:LiSAF we have developed a femtosecond Cr:LiSAF laser system with a final amplifier aperture of 25 mm using chirped pulse amplification. This system currently produces 90-fs output pulses with a peak power of 8 TW. Its configuration is shown in Fig. 1. The laser system uses a Kerr-lens mode-locked Ti:sapphire laser, a pulse stretcher, a regenerative amplifier followed by three additional double pass amplifiers with increasing aperture up to 25 mm and a pulse compressor. Details of this laser system are described elsewhere. The energy of the single pulse selected by the pulse slicers at the output of the regenerative amplifier is 4.5 mJ with a stability of better than ±5%. When directly compressed it reliably produces 2.5 mJ (sech2) pulses of 95 fs duration in a diffraction limited Gaussian beam. The spectral width of the amplified pulse is 8.5 nm resulting in a time-bandwidth product of 0.32 which is close to the Fourier-transform limit of 0.32. The 7 mm preamplifier then produces pulse energies of 75 mJ at a repetition rate of 1 Hz which are then further amplified by the 10 mm amplifier to 280 mJ at the same repetition rate. Two additional passes through the 25 mm final amplifier results in 1.45 J pulse energy in a single shot mode (1 shot/10 min) in a approx.2x diffraction limited beam. After recompression the pulse energy is 750 mJ. A single shot autocorrelation of these pulses is shown in Fig. 2. The measure (FWHM) width is 140 fs, which corresponds to a pulse duration of 90 fs assuming a sech pulse shape. We are now making further improvements to the output performance of this system. We estimate that the final amplifier with 25 mm aperture can support pulse energies of several joules. Replacement of some of the amplifier crystals with low-loss Cr:LiSAF will lead to a 3x increase in output power and an improvement in focus-ability. In addition, a further increase of a factor of 2 can be gained from anti-reflection coatings to all our amplifier rods. We also envisage to redesign the system for minimum third and higher order dispersion to amplify pulses much shorter than 100 fs. We believe that with some of these improvements our laser system has the potential to reliably provide focused intensities well in excess of 1020 W/cm2 in the near future

Optimum microchannel plate (MCP) configuration for use in high-speed, high-resolution x-ray imaging

Microchannel plates (MCPs) are incorporated in a wide variety of x-ray imaging and detection devices. Experimental measurements are presented in this paper which are used to determine the MCP and phosphor configuration for optimizing spatial resolution, temporal resolution, and gain in an x-ray framing camera. We investigate with the use of pulsed electron accelerating voltages to attain extraction fields higher than those possible at safe DC levels. In addition, MCPs with exit faces coated with an insulating material, in order to increase the maximum safe DC electron extraction field, were also tested