Yasutomo Shiomi

Characterization of frequency-tripled nanosecond pulsed Ti:sapphire laser injection seeded by a frequency-scanning cw Ti:sapphire laser by use of optogalvanic spectroscopy of silicon atoms

The performance of a narrow-linewidth nanosecond pulsed deep-UV coherent light source consisting of a frequency-tripled nanosecond pulsed Ti:sapphire laser injection seeded by a frequency-scanning cw Ti:sapphire laser has been characterized by using optogalvanic spectroscopy of silicon atoms as a diagnostic. The envelope of the optogalvanic spectrum indicates the pure Doppler broadening of silicon atoms, which was estimated to be as broad as 4 GHz, without the broadening effect from the laser linewidth itself.

Nanosecond 389-nm coherent light source with injection seeding for nuclear spin polarization of 3He atoms

We have developed a 389-nm frequency-doubled nanosecond-pulsed coherent light source with injection seeding for nuclear polarization of 3He atoms with 23S→33P and then suggested four kinds of spectroscopic methods with the injection-seeded light source. With this light source, we have conducted saturated absorption spectroscopy of metastable 3He atoms. As a result, an accurate resonance frequency of 770682 GHz and a dip width of 1.7 GHz of metastable 3He atoms are obtained. Therefore, the linewidth of our injection-seeded light source can be estimated at 65 MHz or 1.7 GHz. Our light source has potential for the polarization of 3He due to high-peak power and narrow linewidth of the injection-seeded light source.

Frequency stabilization of nanosecond deep-ultraviolet coherent light source with injection seeding

We have developed the advanced technology for the frequency stabilization of a nanosecond deep-ultraviolet coherent light source toward manipulating semiconductor atoms by injection locking with a single-frequency Ti:sapphire laser. In order to stabilize injection seeding, we utilized the small change of the build-up time of the slave-laser pulse. The injection-locked laser can acquire significant performances of both narrow linewidth and high peak power. As a result, the fluctuation of the wavelength decreases from 2.1 GHz to 10 MHz due to the injection seeding. The laser performance indicates various potentials useful for manipulating semiconductor atoms.

Development of a single-frequency nanosecond pulsed deep-UV coherent light source for manipulating silicon atoms

A single-frequency nanosecond pulsed deep-ultraviolet coherent light source consisting of a frequency-tripled nanosecond pulsed Ti:sapphire laser injection-seeded by a single-frequency cw Ti: sapphire laser was developed for manipulating silicon atoms. The long-term single-frequency operation was demonstrated successfully with matching between the optical frequency of the seed laser and the cavity frequency of the slave laser with build-up time locking electronics.

Atomic layer deposition of atomic mirror for silicon

There have been significant progresses in atom optics utilizing laser cooling techniques in recent years. Among them, we have been interested in an atomic mirror for silicon which can reflect silicon atoms. The atomic mirror consists of two layers on a sapphire substrate, and then atoms are reflected by the dipole forces from evanescent waves caused by the light reflected internally and totally at the interface of different refractive indices. In this study, we have constructed some structures of the atomic mirror. We tried atomic layer deposition techniques for preparation of both Al2O3 and TiO2 thin films, whose surface and interface roughnesses are well suppressed. In order to achieve the predicted enhancement of the evanescent waves, atomic layer deposition of the layer with the higher refractive index is especially important. It has found that absorption can be suppressed considerably by adding Al(CH3)3 precursor gas to the alternate introducing cycle of TiCl4 and H2O2 precursor gases. We use this effect which can improve homogeneity and flatness of layers significantly, to design an atomic mirror using atomic layer deposition.

Single-frequency stabilization of frequency-tripled nanosecond Ti:sapphire laser injection-seeded for silicon atom optics

A frequency-tripled nanosecond pulsed Ti:sapphire laser injection-seeded by a cw single-frequency Ti:sapphire laser has been developed. The single-frequency stability of this light source is demonstrated successfully by matching between the optical frequency of the seed laser and the cavity frequency of the slave laser with build-up time electronics. It is also discussed with fluctuations of the wavelength of the Ti:sapphire laser and the optogalvanic signal of silicon atoms. This unique light source opens the door to silicon atom optics, which is capable of manipulating atoms isotopically for novel material processing.

Development of an injection-seeded nanosecond pulsed deep-UV coherent light source for controlling silicon atomic waves

Output performances of the injection-seeded narrow-linewidth nanosecond pulsed deep-ultraviolet coherent light source we developed here are discussed with the optogalvanic spectroscopy of silicon atoms. The spectroscopy indicates its potentials useful for controlling atomic waves resonantly.