Yuichiro Yano

Conference Proceedings 2024 IEEE International Symposium on Mixed and Augmented Reality Adjunct Ismar Adjunct 2024 · January 1, 2024 In this paper we explore the potential of utilizing Virtual Reality (VR) as a therapeutic tool for supporting individuals in the LGBTQ+ community, who often face elevated risks of mental health issues. Specifically, we investigated the effectiveness of usi ... Full text Cite

Evaluation of Stability of Higher-Order Atomic Clocks by Higher-Order Allan Variance

Conference IFAC Papersonline · July 1, 2023 In this paper, we analyze a generalized version of the Allan variance, referred to as a higher-order Allan variance, that can evaluate the frequency stability of multi-dimensional atomic clocks as a function of the measurement interval. It is known that th ... Full text Cite

Impact of FBAR Oscillator Stabilized to the CPT Resonance as Local Oscillator of Millimeter-Wave Communications

Conference IEEE International Ultrasonics Symposium Ius · January 1, 2023 We verified the applicability of FBAR oscillators to local oscillators (LOs) in millimeter-wave communications (MMWc). Assuming the development of an oscillator chip that operates in the extra-high-frequency (EHF) band, which is a key component of an LO in ... Full text Cite

Equivalence of JST Algorithm and Kalman Filtering Algorithm for Time Scale Generation

Conference IEEE International Symposium on Precision Clock Synchronization for Measurement Control and Communication Ispcs · January 1, 2023 Existing studies have established two different algorithms, the Kalman filtering algorithm and the Japan Standard Time (JST) algorithm, for generating reliable time scales. However, the relations between those two methods have not been clarified. In this p ... Full text Cite

Spectral Decomposition in Kalman Filter Algorithm for Homogeneous Atomic Clock Ensembles

Conference Proceedings of the IEEE Conference on Decision and Control · January 1, 2023 Existing studies have pointed out numerical instability in the Kalman filter of atomic clocks, but the reasons for such instability have not been clarified mathematically. In this paper, we mathematically clarify the reason for the numerical instability by ... Full text Cite

FBAR Oscillator and MEMS Tunable VCSEL to Generate the Probe Lasers for Microfabricated Atomic Clock

Conference IEEE International Ultrasonics Symposium Ius · January 1, 2022 In this paper, we describe several new approaches to cost reduction for the realization of ultraminiaturized atomic clocks. One is the development of a wavelength tuner for vertical-cavity surface-emitting lasers (VCSELs) for the atomic clocks. Our VCSEL i ... Full text Cite

Evaluation of New Solid Rubidium Source Using Atomic Clock Stabilization Loop

Conference 21st International Conference on Solid State Sensors Actuators and Microsystems Transducers 2021 · June 20, 2021 We synthesized and evaluated rubidium azide as a new solid alkali metal source for microfabricated atomic clocks. A MEMS-based gas cell was filled with Rb as the alkali metal source for activation and a buffer gas (N2 or Ar), and the frequency stability wa ... Full text Cite

Study of 3-GHz-band Thin-film Bulk Acoustic Resonator Oscillators for Microfabricated Atomic Clocks

Conference IEEE International Ultrasonics Symposium Ius · January 1, 2021 Ultracompact and ultrastable clock chips are essential for beyond 5G/6G (b5G/6G) telecommunication systems, and we are studying 3-GHz-band thin-film bulk acoustic resonator (FBAR) oscillators for the development of such clock chips. Good frequency instabil ... Full text Cite

FBAR-based frequency divider oscillator for lock-in amplifier free atomic stabilization loop

Conference IEEE International Ultrasonics Symposium Ius · September 7, 2020 We developed an injection-locking-type frequency-2-divider oscillator using a thin-film bulk acoustic resonator (FBAR) to achieve the ultrastabilization of frequency using the coherent population trapping (CPT) resonance of the 87Rb atom. When receiving th ... Full text Cite

Injection Locking Type 1/2 Frequency Divider Employing Piezoelectric MEMS Resonator for Simplifying the Micro Atomic Clock System

Conference Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems MEMS · January 1, 2020 This paper is the first report on injection-locking-type frequency dividers incorporating a piezoelectric MEMS resonator. It gives us a new step toward the ultraminiaturizion of atomic clocks to the chip level. Our devices can divide the 6-GHz-band RF sign ... Full text Cite

Drift-free FBAR oscillator using an atomic-resonance-stabilization technique

Conference IEEE International Ultrasonics Symposium Ius · October 1, 2019 We developed a thin-film bulk acoustic resonator oscillator (FBAR-OSC) with drift-free and excellent frequency stability. The FBAR-OSC outputted the 3.5 GHz band oscillation and successfully stabilized it employing the coherent population trapping (CPT) re ... Full text Cite

A Reflection Type Vapor Cell Based on Local Anodic Bonding of 45° Mirrors for Micro Atomic Clocks

Conference 2019 20th International Conference on Solid State Sensors Actuators and Microsystems and Eurosensors Xxxiii Transducers 2019 and Eurosensors Xxxiii · June 1, 2019 This paper reports the design, fabrication and evaluation of a reflection-type micro Rb vapor cell fabricated by local anodic bonding of small 45° mirrors. The 45° mirrors with a Bragg reflector are fabricated by using dicing process. The vapor cells havin ... Full text Cite

Design of the BP-COG Study of Blood Pressure Over the Life Course and Later-Life Cognition in Blacks, Hispanics, and Whites: A Pooled Cohort Analysis of ARIC, CARDIA, CHS, FOS, MESA, and NOMAS.

Conference STROKE · February 1, 2019 Link to item Cite

A Reflection-Type Vapor Cell for Micro Atomic Clock

Conference Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems MEMS · January 1, 2019 This paper reports the design, fabrication and evaluation of a reflection-type Rb vapor cell with a Glass/Si/Glass structure for chip-scale micro atomic clocks. To miniaturize the cell and obtain a Rb resonance signal with a high sensitivity, long laser li ... Full text Cite

Study of Quantitative Calculation of CPT Resonances Considering Zeeman Sub-Levels of CS-D1 Line

Conference Ifcs 2018 IEEE International Frequency Control Symposium · December 31, 2018 We developed a simulator that calculates the CPT resonances of all the energy levels of the Cs-Di line. The simulator can analyze the CPT resonances of not only the clock transition but also all the Zeeman sub-levels. To verify this calculation result, we ... Full text Cite

Micro atomic frequency standards employing an integrated FBAR-VCO oscillating on the 87RB clock frequency without a phase locked loop

Conference Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems MEMS · April 24, 2018 We applied a 3.5-GHz-band thin film bulk acoustic resonator (FBAR) to a voltage controlled oscillator (VCO), which is designed as a local oscillator of miniaturized atomic frequency standards (AFSs). This frequency reference instead of a bulky quartz reson ... Full text Cite

FBAR Oscillator Stabilized by Rb Atomic Resonator for SHF/EHF-Band Wireless Devices

Conference IEEE International Ultrasonics Symposium Ius · January 1, 2018 We propose an FBAR oscillator for the wireless system used in the superhigh-frequency (SHF) band or extremely high-frequency (EHF) band. At these frequencies, a high-precision standard clock is required, and it is preferable that the clock frequency be set ... Full text Cite

Theoretical and experimental study of Rb coherent population trapping atomic clock with phase modulation detection

Conference 2017 Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium Eftf Ifc 2017 Proceedings · October 27, 2017 We theoretically and experimentally study Coherent Population Trapping (CPT) resonance with phase modulation detection. We measured the time response behavior of CPT resonance using an 87Rb gas cell and the D1-line vertical-cavity surface-emitti ... Full text Cite

Estimation of the light shift in Ramsey-coherent population trapping

Conference 2015 Joint Conference of the IEEE International Frequency Control Symposium and the European Frequency and Time Forum Fcs 2015 Proceedings · June 29, 2015 We both numerically and analytically investigate on the light shift in Ramsey-CPT resonance for compact atomic clocks. The numerical calculation of the light shift is based on a density matrix analysis in Λ-type three state model. And the analytical method ... Full text Cite

CPT pulse excitation method based on VCSEL current modulation for miniature atomic clocks

Conference 2015 Joint Conference of the IEEE International Frequency Control Symposium and the European Frequency and Time Forum Fcs 2015 Proceedings · June 29, 2015 We propose a coherent population trapping (CPT) pulsed-excitation method based on direct drive-current modulation of a vertical-cavity surface-emitting LASER for miniature atomic clocks (MACs). Because our method needs only a simple device configuration wi ... Full text Cite

Investigation on light shift in CPT-Ramsey resonance for compact atomic clocks

Conference Ifcs 2014 2014 IEEE International Frequency Control Symposium Proceedings · January 1, 2014 This paper presents a theoretical and experimental investigation on the light shift (AC Stark shift) of the 62S1/2 (F = 3 ↔ 4) transition in 133Cs, as observed through coherent population trapping (CPT) under a pulsed excit ... Full text Cite

Study of an observation method based on crossed polarizers for high-contrast coherent population trapping

Conference 2013 Joint European Frequency and Time Forum and International Frequency Control Symposium Eftf Ifc 2013 · December 1, 2013 In this paper, we propose an observation method based on crossed polarizers to obtain high-contrast coherent population trapping (CPT) resonance with parallel linearly polarized light (lin 11 lin field). Experimental results show that a high resonance cont ... Full text Cite

Higher-order sideband excitation method for pulsed CPT atomic clock

Conference 2013 Joint European Frequency and Time Forum and International Frequency Control Symposium Eftf Ifc 2013 · December 1, 2013 We propose a higher-order sideband excitation method combined with pulse excitation to reduce power consumption of coherent population trapping (CPT) atomic clocks. Since higher-order sideband excitation enables reduction of radio frequency (RF), our metho ... Full text Cite

Real-time three-dimensional vibration mode visualization system based on laser speckle interference

Conference 2010 IEEE International Frequency Control Symposium Fcs 2010 · October 19, 2010 In this paper, we describe an improved system that visualizes the 3-D vibration modes on the device surface in quasi-real time without precision optical adjustment. We used three visible semiconductor lasers with adequately separated wavelengths. The incid ... Full text Cite

Mode shape measurement system with temperature variation function

Conference 2010 IEEE International Frequency Control Symposium Fcs 2010 · October 19, 2010 A measurement system with a temperature control function was developed for mapping the vibration patterns of piezoelectric resonator devices. This system is based on the laser speckle method with intermittent device excitation. By use of a small oven with ... Full text Cite