Ken-ichi Watabe

Learn More
High-contrast coherent population trapping signals were observed on the Cs D1 line by use of a bichromatic linear polarized light (lin‖lin field). A maximum absorption contrast of about 10% was obtained. This was nearly twice as high as that measured with the standard configuration of bichromatic circularly polarized light (σ-σ field). The results are(More)
The frequency stability of an atomic fountain clock was significantly improved by employing an ultra-stable local oscillator and increasing the number of atoms detected after the Ramsey interrogation, resulting in a measured Allan deviation of 8.3 × 10(-14)τ(-1/2)). A cryogenic sapphire oscillator using an ultra-low-vibration pulse-tube cryocooler and(More)
Technical issues are investigated for a precise frequency transfer system using two-way signals by wavelength division multiplexing (WDM) in a single fiber. Bi-directional optical amplifiers are necessary to make the distance longer. Frequency stability is shown in the tandem optical amplifier link where the amplified spontaneous emission (ASE) noises are(More)
This paper presents a complete monolithic 500V, 1A three phase motor driver. The single chip is composed of n-ch. lateral IGBTs, HV-diodes, 24V CMOS and HV-NMOS structures fabricated on an SOI (Silicon On Insulator) substrate using trench isolation techniques. The chip is assembled into a newly designed surface mount SOP (small outline package) with a body(More)
  • 1