Abstract: An SHG autocorrelator for use in measuring the duration of an ultrashort pulse of light includes in one embodiment a thin pellicle beamsplitter for splitting the pulse of light into first and second beams, a stationary optical delay disposed along the path of the first beam, a movable optical delay disposed along the path of the second beam, a thin SHG crystal, a concave mirror for bringing the first and second beams to focus into the SHG crystal, a photodetector for detecting light emitted from the SHG crystal, and a narrow bandpass filter in front of the photodetector for filtering out non second harmonic light. The device reduces time broadening and delay of ultrashort pulses in the femtosecond time domain.

Abstract: A method and apparatus for generating a light pulse having a duration as short as about 3 picoseconds is disclosed. A 5 mJ 25 picosecond second harmonic light pulse from a Nd:YAG laser system is focused into a 5 cm cell filled with D.sub.2 O so as to generate a continuum light pulse spanning about 150 nanometers with an average energy of at least 20 nd/nm across the spectrum. The continuum light pulse is fed through a 10 nanometer narrowband filter centered at 580 nanometers, producing an output pulse having a duration of about 3 picoseconds. The pulse so produced has a number of uses including as a seed pulse for dye laser oscillators and solid state amplifiers or as a pump source for pumping ultrashort dye lasers.

Abstract: A laser is disclosed which includes an optical path length extender for increasing the optical path length of the laser cavity. The path length extender, which is disposed inside the laser cavity itself, includes a set of three curved mirrors each having the same curvature. The three mirrors are spaced and angularly positioned such that light entering the path length extender is reflected back and forth about the three mirrors a defined number of times before exiting the path length extender. By rotating one or two of the mirrors the number of reflections within the set of mirrors can be changed. The laser cavity configuration is particularly useful in a pulse laser for increasing the optical path length of the cavity for the purpose of increasing the pulse to pulse separation of the emitted pulses, when such an increase is desired, but is not limited exclusively to pulse lasers.

Abstract: An arm lever for use on exercise equipment. The arm lever includes a handle, a support member and a connecting mechanism for connecting the handle to the support member. The connecting mechanism enables the handle to be oriented at any one of a number of different angular positions relative to the support member and releasably locked in place at the desired angular position. The particular angular position chosen is dependent on the exercise being conducted.

Abstract: Athletic legwear designed especially for use by a person while engaged in aerobic exercise includes a pair of pants of approximately knee-length. A plurality of pocket assemblies are removably attached to the pants between the waist and knee of the wearer, each pocket assembly having one or more pockets adapted to hold securely therein one or more weights.

Abstract: An oscilloscope constructed for use in real time resolving an ultrafast voltage signal includes a streak camera having a transmission line photocarthode, a constant light source for illuminating the photocathode, an input coupled to the transmission line photocathode, an accellerating mesh, a pair of sweep electrodes, electron multiplication means, a phosphor screen and a DC high voltage source. In use, the voltage signal to be examined is applied to the input. When the voltage signal on propagating through the photocathode intersects in time and space on the photocathode with the light from the light source, a number of electrons proportional to the intensity of the voltage signal are emitted from the photocathode. These electrons are then accelerated, deflected by the pair of sweep electrodes, multiplied by the microchannel plate and then impinge upon the phosphor screen, creating an optical image having an intensity proportional to the number of impinging electrons.

Abstract: A laser system in which the laser medium is a single crystal of Cr.sub.3+ :Mg.sub.2 SiO.sub.4 is disclosed. In one embodiment, the system comprises a single crystal of chromium doped forsterite and a cavity which includes a pair of 30 cm. radius mirror having high transmission at 543 nm (the pump wavelength) and high reflectivity in the 1150-1350 nm range. Room temperature vibronic pulsed laser action is obtained with this cavity. Laser action has been observed at 1235 nm and a bandwidth of 25 nm. The wavelength range is suitable for transmission through optical fibers and is useful in laser ranging and remote sensing. Because of the ultrawide fluorescence bandwidth and a 15 fluoroescence lifetime the system is suitable for high intensity, tunable, cw, Q switched mode locked operation. In the mode locked operation pulses as short as 10-500 femtosecond may be generated. A number of different embodiments of the invention are described.

Abstract: A method and apparatus for detecting the presence of cancerous tissue using visible luminescence. The tissue to be examined is excited with a beam of monochromatic light that causes the tissue to fluoresce over a spectrum of wavelengths. The intensity at which the excited tissue fluoresces can be measured either over a spectrum or at a predetermined number of preselected wavelengths. By determining the wavelength(s) at which maximum intensity(ies) are attained for the tissue in question and by comparing these peak wavelengths, either visually or electronically, to the peak wavelength(s) derived from a known non-cancerous tissue, or by comparing the spectrum of the excited tissue with the spectrum of a known noncancerous tissue one can determine the carcinomatoid status of the tissue in question.

Abstract: A femtosecond sampling oscilloscope includes a femtosecond laser for generating a pulse of light in the femtosecond range and a beam splitter for splitting the pulse of light into pulses traveling along first and second beam paths. A photoconductive switch disposed along the first beam path is used to produce an electrical stimulus output at a first output port, an electrical pulse output at a second output port and an optical output at a third output port. A photomultiplier tube having a strip line photocathode receives the pulse of light traveling along the first beam path. An input port is coupled to the photocathode. In use, the output signal at one of the output ports is connected to a test device producing a test voltage signal which is applied to the input port. When the test voltage signal and the light pulse traveling along the second path intersect on the photocathode in space and time, an electrical signal output is produced at the photomultiplier tube.

Abstract: A braiding machine for use in applying a tubular shaped braid around a product includes a closed loop induction heater for applying heat to the product as it is being fed through the braiding machine before it is wound on a take-up reel for use or further processes. The induction heater includes an inductor and a pair of pulley wheels and is attached to the frame of the braiding machine by a pair of brackets. The heater can be by-passed if the product does not require heat. The braiding machine is especially useful in applying a tubular metal braid over an insulated wire core which is itself covered by a served metal coated mylar strip having a heat sensitive adhesive on one surface which must be activated before the product is complete.

Abstract: A technique for performing multiplication oriented optical digital computations in which a pair of identical primary frequency coherent beams of light are directed off-axis through a second harmonic generating crystal to produce an on-axis frequency doubled (i.e. second harmonic) output signal. Each primary beam is encoded with one of the quantities to be multiplied producing an output beam containing the product of the two quantities. The output beam is detected by an array type detector. The technique can be used in performing time integration applications as well as spatial integration applications. For space integration applications a cylindrical lens is positioned in front of the array detector. Multistage operations are realized using a parameteric frequency down conversion and amplification scheme.

Abstract: A display which is in the form of a sheet of transparent material having imprinted on one side thereof the upper portion of a head of an animal and having on the other side a layer of a non-permanent adhesive. The display is mounted on the rear window of an automobile, the automobile being of the type which includes a brake light on the rear window. The display is mounted on the window such that the brake light is where the nose of the animal would be located. In use, when the brakes are applied, the brake light is turned on giving the appearance that the nose intermittently lights up.

Abstract: An apparatus and method are disclosed for detecting the presence of particles on the surface of an object such as the front side of a patterned semiconductor wafer. A collimated beam of light is directed onto an area on the surface of the object at a grazing angle of incidence. A detector positioned above the surface detects light scattered from any particles which may be present on the surface, but not specularly reflected light. The output of the detector is fed into a computer where the information is processed and then displayed on a display. The surface is prepositioned relative to the incident light beam so that the diffracted light from the surface and the pattern on the surface is at a minimum. The object is then moved translationally to expose another area to the incident light beam so that the entire surface of the object or selected portions thereof can be examined, an area at a time.

Abstract: An apparatus for making ac surface photovoltage (SPV) measurements of a specimen of semiconductor material under dc bias voltage conditions includes a light source whose output beam is intensity modulated, an adjustable dc bias voltage source, a conductive base for supporting the specimen and a novel capacitance type reference electrode assembly for sensing the SPV signals. The reference electrode assembly includes in one embodiment a transparent flexible sheet of insulating material having on one surface a first conductive coating which serves as a reference electrode and a second conductive coating which serves as a guard electrode, the first coating being transparent. The flexible sheet of insulating material is attached to a flat glass plate through an annular spacer. An elastomeric button is positioned between the sheet and the glass plate.

Abstract: A safety gate which is adapted to be mounted on the sidewalls at the top or bottom of a stairway to prevent unwanted access thereto by a toddler or on the sidewalls of a door frame or other structure to prevent unwanted passage therethrough from either direction by a toddler includes a mounting rail which is adapted to be fixedly attached to one of the sidewalls, a locking post which is adapted to be fixedly attached to the other sidewall opposite to the mounting rail and a gate frame assembly which is adapted to be removably and pivotally mounted to one end to the mounting rail and secured at the other end, when desired, to the locking post. When the gate frame assembly is mounted on the mounting rail, the gate frame can be pivoted back and forth like a swinging door when restricted passage is not desired and then locked to the locking post when restricted passage is desired.