Abstract: A device and methods for the real-time monitoring of stem cells in a stem cell transplant. The device comprises a linear member and particle detection device configured to occupy the lumen of a catheter while the catheter is in place to administer a stem cell transplant to a delivery site in the body of a patient. Monitoring of the stem cells permits the device to provide signals to a computer processor for the determination of one or more characteristics of stem cells in the stem cell transplant.

Abstract: A device and methods for the real-time monitoring of stem cells in a stem cell transplant. The device comprises a linear member and particle detection device configured to occupy the lumen of a catheter while the catheter is in place to administer a stem cell transplant to a delivery site in the body of a patient. Monitoring of the stein cells permits the device to provide signals to a computer processor for the determination of one or more characteristics of stein cells in the stein cell transplant.

Abstract: A polarization insensitive mirror (3) comprises a single homogeneous coating (1) coated onto a typically metallic reflective surface (2). The mirror (3) is substantially insensitive to polarization of incident radiation (4) over a wide range of angles of incidence (A). The coating (1) has an index of refraction (n) greater than 2.4, is substantially transmissive to the incident radiation (4), and has a thickness (t) substantially equal to L.sub.0 /2n, where L.sub.0 is the wavelength of the incident radiation (4) in freespace. Germanium makes a good coating (1). The reflective surface (2) is typically gold or silver. Increasing slightly the thickness (t) of the coating (1) increases the range of incident angles (A) over which the mirror (3) exhibits minimized phase differentials (B). Graphs (FIGS. 3-8) are presented comparing the reflectivity, phase differential (B), and average reflectivity of mirrors (3) fabricated according to the teachings of the present invention with those of the prior art.

Abstract: An improved detector array for scan receiver applications whereby each contiguous element of the array is connected to a summing port with its adjacent element.

Abstract: A laser radar transmitter (2) has, associated with a single active lasing region (11) and preferably in the same laser cavity (1) therewith, an amplitude modulator (21) and a frequency modulator (25), which may simultaneously place continuous AM and continuous FM on a single output beam (7). Amplitude modulator (21) is preferably an EO crystal having a high EO coefficient, low loss, and field-induced birefringence. Frequency modulator (25) is preferably an EO crystal having a high EO coefficient, low loss, and a field-induced index change. Applying a d.c. driving voltage to the AM crystal (21) and an a.c. driving voltage to the FM crystal (25) produces an output beam (7) having FM. Applying an a.c. driving voltage to the AM crystal (21) produces an output beam (7) having AM, independently of whether FM is added by means of applying an a.c. driving voltage to the FM crystal (25).

Abstract: An optical sensor has a gain medium situated at a first location and defines one end of a resonating optical cavity. An optical fiber couples electromagnetic radiation to a predetermined point at a second location where it is directed toward a reflective surface. The physical condition to be sensed causes the reflective surface to move with respect to the end of the optical fiber. This movement essentially changes the length of the cavity in which the electromagnetic energy is resonating causing a corresponding change in the axial mode difference frequency within the cavity. A small portion of electromagnetic energy is coupled out of the cavity at the first location to a photodetector. Finally, the photodetector creates an electrical signal which varies as the change in the axial mode difference frequency, thus indicating the change in the physical condition.

Abstract: An improved electrode configuration and method for the deposition of electrical power into an electric discharge laser having a gas path transversely disposed to an optical axis and the electric field is disclosed. The electrode configuration includes a cathode, having one or more common geometry rod elements of a thoriated material disposed transverse to a gas path and a planar anode disposed opposite the cathode in a parallel relationship thereto wherein the cathode and the anode define the gas path therebetween. The electrode configuration is adapted for operation without ballast resistance in the electrical circuit and without the utilization of preionization means. The electrode configuration provides a discharge having substantially diffuse and uniform characteristics within the discharge region.

Abstract: A closed cycle chemical laser adapted for continuous wave operation is disclosed. A first gas such as sulphur hexafluoride is decomposed by an electrical discharge means to provide at least some fluorine atoms which when combined with molecular hydrogen in a mixing chamber located upstream of and proximate to an optical power extraction chamber forms an excited laser species capable of stimulated emission to produce a continuous wave output beam. After passing through the optical cavity the effluent is purified by selective absorption and adsorption processes to eliminate the laser species from the effluent and to separate the hydrogen for recirculation back to the mixing chamber. The remaining effluent has its pressure increased, is supplemented with makeup feed gases and is recycled. The operation of the system using sulphur hexafluoride and hydrogen gases is discussed in detail and various combinations of other suitable reactants are disclosed.

Abstract: A method for cavity dumping a Q-switched laser having a gaseous gain medium to obtain submicrosecond output pulses, typically controllably variable between ten and three hundred nanoseconds at a high pulse repetition frequency typically up to at least twenty-five thousand pulses per second is disclosed. In a laser adapted for continuous wave operation, a combination of a retardation element and an electrooptic modulator provides a first polarization state to intracavity radiation incident onto an intracavity polarization coupler oriented to couple out of the cavity radiation having the first polarization state to provide a high loss condition to the cavity to maintain the laser below threshold. A voltage applied quickly to the modulator converts the first polarization state to a second polarization state to provide a low loss condition to the cavity to Q-switch the laser.

Abstract: A laser having a gaseous gain medium capable of continuous wave operation and including an etalon with a Stark active gas disposed therein, adapted for providing submicrosecond pulses is disclosed. A method of utilizing the Stark effect to tune rapidly an etalon to form an output mirror having a variable reflectivity to Q-switch and cavity dump the optical flux within a laser to provide an output pulse of laser radiation having a submicrosecond pulse width, typically variable between fifty and three hundred fifty nanoseconds, at a pulse repetition frequency up to twenty-five kilohertz is disclosed. A laser typically having a carbon dioxide gain medium adapted for continuous wave operation includes a grating defining one end of the laser resonator and an output mirror defining the other end wherein the output mirror is an etalon formed with two mirrors containing a switching cell having a Stark active gas disposed therein.

Abstract: A dual-beam amplitude-modulated laser transmitter/receiver suitable for laser-radar applications is scalable to high powers because there is no active modulator element that the laser beam passes through. The transceiver comprises a laser source with two separate independent laser optical cavities. Each laser cavity is similar, but each operates at its own frequency. Signals from the two cavities are superimposed at a combining beam splitter to form two transmitter output beams with each combined beam intensity modulated at the laser difference frequency. The output consists of two beams separated in elevation and with equal beam powers from each laser cavity the intensity modulation is 100%. Each beam has its own homodyne detector and separate local oscillator. Thus, each beam path is considered to be a distinct homodyne transceiver. If the frequency of one of the laser sources is changed in time, an AM/FM/CW output suitable for absolute range measurements and fine doppler is generated.