Unidirectional travelling wave operation of a mode-locked Nd:glass ring laser
Abstract The development of unidirectional mode-locked pulses in a Nd:glass ring laser is studied for various combinations of active and passive mode-locking and pulse direction discrimination elements.
Active-passive mode-locked Nd:YAG oscillator.
An active-passive mode-locked Nd:YAG oscillator provides greatly improved shot-to-shot reproducibility compared with passive mode-locking. Effects of modulator drive power, laser cavity length, and intracavity etalons on the pulse width and stability are given. Using two-photon-fluorescence techniques the pulse width was 35.9 +/- 1.7 psec and the corresponding pulse energy was 166 +/- 6 microJ.
Clustering phenomena in low-pressure reactive plasmas. Basis and applications
Abstract Clustering phenomena of particles below a few nm in size in low-pressure reactive plasmas have been studied in capacitively coupled high-frequency SiH4 discharges. Clusters nucleate around a size of 0.5 nm, Si4Hx and subsequently grow due to influxes of SinHx (1 < n < 4) and other molecular species. Because of long gas-residence time and small surface loss-probability of clusters, even neutral ones accumulate to nucleate in the reactor. Appearance of negatively charged clusters is considered to become noticeable at around Si4Hx. The growth of clusters is suppressed by using thermophoretic force, gas flow, periodical discharge modulation, and hydrogen dilution. The reactor has been newly developed to suppress the growth of clusters both by thermophoretic force and by gas flow and evacuation without stagnation. Using the reactor, a-Si:H films of extremely high quality have been successfully deposited.