Kenneth J. Teegarden

Time resolved spectroscopy of large bore Xe flashlamps for use in large aperture amplifiers.

Time resolved spectroscopy was performed on 13-mm xenon filled flashlamps. The use of a well-characterized system allowed the acquisition of absolute radiometric data. The data were compared to the predictions of a phenomenological flashlamp model and differences noted. Specifically the arc for equal currents is not the same for dI/dt > 0 and dI/dt < 0, the continuum is a stronger function of current density than the model indicated, and different lines, linewidths, and line intensities were found.

Faraday Rotation Optical Isolator for 10.6-μm Radiation

Measurements that have been performed indicate that hot-pressed ferromagnetic CdCr(2)S(4) would be a useful Faraday optical isolator material for laser systems at 10.6 microm. A large-aperture, liquid-nitrogen-cooled isolator, requiring modest magnetic fields with material of optimum thickness, would provide isolation in excess of 30 dB with insertion loss due to optical absorption in the active element of less than 3 dB. Consideration of its figure of merit indicates that hot-pressed CdCr(2)S(4) could be used as an isolator at 1.06 microm, introducing less than 2 dB insertion loss due to optical absorption at that wavelength.

Picosecond time-resolved spectroscopic study of vibrational relaxation processes in alkali halides

Abstract The luminescence properties of various kinds of impurities in alkali halides are studied with 1 ps timing accuracy. The relation between measured vibrational relaxation times, vibronic spectral structure and impurity-lattice coupling strength is investigated.

Dynamic pumping model for amplifier performance predictions.

Based upon time resolved spectroscopy of 13-mm xenon filled flashlamps, we have constructed a unique dynamic pumping model to predict the gain performance of active mirror amplifiers. The model, which includes the effects of spontaneous emission, concentration quenching, water quenching, and amplified spontaneous emission, uses only spectroscopy data from small glass samples as input. The use of the model in amplifier/system optimizations will be described.

Self-starting mode-locked erbium fiber laser using grating reflectors

The construction and operating characteristics of a compact self starting mode locked erbium fiber laser are described in this paper. The laser employs a Fabry-Perot cavity with a fiber grating as one reflector and a nonlinear mirror based on a saturable absorber as the other. It operates at a pump power of less than 50 mW and produces mode locked pulses of 16.5 ps duration at a frequency of 3.25 MHz and a peak power of about 20 W.

Nonlinear optical properties of semiconductor quantum well structures near 1.55 μm

We present an experimental study of mode-locking in linear- cavity erbium-doped fiber lasers which use MQW mirrors as saturable reflectors. From the results of single-beam, nonlinear transmission measurements, we have found the saturation intensity of the MQW mirrors to be greatly dependent on the wavelength of the incident radiation with respect to the MQW bandedge. For satisfactory mode-locked laser performance, we have found that the MQW mirrors must have a sufficiently high saturation intensity to provide the required intensity discrimination to initiate and sustain modelocked operation.

Electrically controlled mode locking of a linear-cavity fiber laser

We describe a simple efficient erbium fiber laser mode locked with a multiple quantum well saturable absorber whose reflectivity can be controlled with an applied electric field. The laser produces 30 ps, duration pulses at a repetition rate of 3.25 MHz.

A Compact Modelocked Erbium Doped Fiber Laser for Field Use

A compact, modelocked erbium doped fiber laser is constructed with fiber Bragg gratings. Passive modelocking is achieved with a MQW saturable absorber microassembled onto the fiber tip. The pulses produced can be used as a source for an OTDR.

Low-threshold passively mode-locked erbium fiber ring lasers

The operating characteristics of a simple self-starting mode-locked erbium fiber ring laser based on a commercial optical fiber gain module are described. The laser produces pulses of the order of 50 mW. In contrast to earlier lasers of the same type, no polarizing element was needed in the ring to initiate mode locking. the implications of this fact relative to possible mechanisms for mode locking are discussed.

Simple passively mode-locked fiber laser oscillator

We report the development of a simple self starting passively mode locked diode pumped laser oscillator utilizing erbium doped fiber and a minimum number of readily available components. With pump powers as low as 8.0 mw, the oscillator generates stable pulses of 1.2 ns width and rates of 5.0 MHz at wavelengths around 1.55 micrometers . Evidence exists for substructure as short as 35 ps within the 1.2 ns pulses. A mechanism for the observed characteristics of the oscillator based on the all optical Kerr effect is proposed.