Holographic devices are expected to have a much larger capacity than conventional optical storage systems such as CD, DVD or blue diode laser based HD-DVD or BD. Recent developments in the field of dedicated recording materials and advanced optical enabling technologies are now opening the door for the realization of commercial products. One of the major technical challenges is the development of a robust and reliable system concept, which allows easy exchangeability of the medium. We developed a holographic tester system with common paths for the reference and the signal beams based on a single mode blue laser diode and a commercial CMOS detector. The system will be used to evaluate various multiplexing schemes, to investigate the influence of system tolerances on the reading performance and to estimate fundamental system limitations.
In order to produce ultrashort far-infrared (FIR) laser pulses we have investigated the superradiance and Raman emission of various molecular transitions optically pumped with the pulses of 10 micrometers -hybrid- or high-pressure single-mode-CO2 lasers truncated within 10 ps. Furthermore we have truncated directly the FIR laser pulses with the first FIR plasma shutter. In our experiments we have observed new phenomena which include e.g. new interrelations between superradiance, swept-gain superradiance and Raman emission, anticorrelated fluctuations of pump radiation versus FIR emission, first optical free induction decay of 10 micrometers -CO2-laser pulses with FIR emitting molecular gases. Finally, we have proved the first spontaneous infrared solitons in stimulated far-infrared Raman scattering on NH3. We have observed solitons in the depletion region of the infrared pump radiation with corresponding dark solitons in the Stokes pulses and detected the laser phase change connected with the soliton generation.
The authors describe the realization of a single-longitudinal-mode high-pressure CO2 laser with a plasma shutter. Single-mode operation is achieved with a three-mirror resonator with etalon. The resonator includes a subcavity, which protects the temperature-controlled etalon from destruction by high radiation intensities. In particular we have investigated two subcavity configurations, which use different etalons and grating arrangements. The maximal pulse energy of about 140 mJ was achieved with a grating that is employed in grazing incidence. A theoretical model has been developed, which illustrates the nonlinear frequency-tuning behavior of the three-mirror resonator and explains how the subcavity has to be adjusted to optimize the mode discrimination of the resonator. With the help of a plasma shutter we have produced tunable truncated 10-μm laser pulses. These pulses were employed to generate 100-ps pulses by optical free induction decay (OFID). With our system we produced for the first time OFID pulses 15 GHz off a CO2 laser line center and investigated the effects of a frequency detuning between the laser frequency and the absorption line of the spectral filter in an OFID system.
In order to produce ultrashort FIR laser pulses we have investigated the superradiance and Raman emission of various molecular transitions optically pumped with the pulses of 10 micrometers hybrid or high-pressure single-mode carbon dioxide lasers truncated with 10 ps. furthermore we have truncated directly the FIR laser pulses with the first FIR plasma shutter developed in our laboratory. In our experiments we have observed new phenomena which include, for example, new interrelations between superradiance, swept-gain superradiance and Raman emission, anticorrelated fluctuations of pump radiation versus FIR emissions, first OFID of 10-micrometers carbon dioxide laser pulses with FIR emitting molecular gases.
By optical pumping of far-infrared (FIR) superradiance and Raman emissions in CH3F, CH3CN, D2O, NH3 with 10 micrometers -TEA-CO2 laser pulses truncated within 10 ps by an IR plasma shutter as well as by first application of a new FIR plasma shutter we have observed new phenomena and generated ultrashort FIR single pulses which are presently applied to investigate the exciting and complicated features of FIR quantum-well detectors and high-TC superconductors.
We generate continuously wavelength-tunable truncated laser pulses with a high-pressure (11 bar) single-mode 10 micrometers CO2 laser and a plasma shutter and applied them to an optical-free-induction-decay (OFID) system. Single- mode operation is achieved using a 3-mirror resonator with etalon. A detailed analysis of this resonator type is presented.