Introduction of Sato lab. in Niigata University Takashi Sato (Prof.), Masashi Ohkawa (Prof.), Kohei Doi (Assistant Professor, Dr.), Shinya Maehara (Research Assistant) Kohei Kawakami (M2), Naoya Shimizu (M1), Yu Ohtomo (B4) Faculty of Engineering Niigata University

Outline 1. Introduction 2. Sato lab. in Niigata University 3. Research project in Sato lab. 4. A Satellite-to-Satellite Interferometry for the Earth’s Gravity Field Determination 5. Our project

Japan Tokyo Niigata City Niigata Prefecture 1. Introduction Niigata University locates at the west side of Niigata City area.

1. Introduction Niigata University locates at the west side of Niigata City area.

1. Introduction Niigata University locates at the west side of Niigata City area. Niigata City Niigata University (13,000 students)

Niigata University has 10 Faculties Faculty of Humanities Faculty of Law Faculty of Economics Faculty of Education and Human Sciences Faculty of Engineering Faculty of Science Faculty of Agriculture Faculty of Dentistry Faculty of Medicine School of Medicine Faculty of Medicine School of Health Science

7 Graduate Schools Graduate School of Education Graduate School of Health Science Graduate School of Modern Society and Culture Graduate School of Science and Technology Graduate School of Medical and Dental Sciences Graduate School of Technology Management Law School

Faculty of Engineering ( 2,200 students ) 7 Departments Mechanical and Production Engineering Electrical and Electronic Engineering Information Engineering Bio-cybernetics Chemistry and Chemical Engineering Civil Engineering and Architecture Material Science and Technology

2. Sato lab. in Niigata University I have one Assistant Professor, one Research Assistant, three Dr. course students, four M2 students, five M1 students, and five undergraduate students in my laboratory. Prof. Ohkawa belongs in Department of Bio-cybernetics. At first, we will make the new team and work on KAGRA project. The member of this team will be: Takashi Sato (Prof.), Masashi Ohkawa (Prof.), Kohei Doi (Assistant Professor, Dr.), Shinya Maehara (Research Assistant) Kohei Kawakami (M2), Naoya Shimizu (M1), Yu Ohtomo (B4)

A Diode Laser Compactness, Maintenance free, Good energy efficiency, durability The oscillation frequency is changeable by the temperature or injection current. The oscillation frequency stabilization Expansion of the application field

A Diode Laser The oscillation frequency is also changeable by a magnetic field. The oscillation frequency control Expansion of the application field

A Diode Laser Its oscillation frequency width is wide compared with other types of lasers. The oscillation frequency narrowing Expansion of the application field

A Diode Laser Its frequency noise is large and wide compared with other types of lasers. Can we use this frequency noise characteristics? Expansion of the application field

3. Research project in Sato lab. Applications using the Beat signal When two lasers which have different frequencies (f 1,f 2 ) are superimposed, we can observe the beat signal, i.e., the frequency difference (f=f 1 -f 2 ), between two lasers.

Generation of THz radiations Select ability of radiation frequency Low cost Compactness Photonic generator of THz wave Using beat signal FOR Wire-less broad-band communication THz imaging +The Oscillation frequency stabilization

Frequency shift observed using in a magnetic field The frequency of the sample VCSEL was set at the shorter wavelength side from that of the reference F.P. type laser, after which we applied the magnetic field, so Fig. 7 shows that the oscillation frequency of our sample VCSEL shifts to the higher frequency side.

Physical random number generation Physical random number generation For the past few years, diode laser’s output intensity noises have been used as the seed for rapid physical random number generation, reaching the Gbit/s range. We, however, generated the physical random numbers from a diode laser’s frequency noise. That is to say, that we converted laser frequency fluctuations directly to fluctuations in the intensity of the light transmitted through the optical frequency discriminator, and then to 8-digit binary numbers, by means of an analog-to-digital converter (ADC).

5. Our project

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