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

NiigataPrefecture

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 LawFaculty of Economics Faculty of Education and Human SciencesFaculty of Engineering 　Faculty of ScienceFaculty of Agriculture 　Faculty of DentistryFaculty of Medicine School of MedicineFaculty 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 EngineeringElectrical and Electronic Engineering

Information EngineeringBio-cybernetics

Chemistry and Chemical EngineeringCivil 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 (f1,f2) are superimposed, we can observe the beat signal, i.e., the frequency difference (f=f1-f2), between two lasers.

Generation of THz radiations

Select ability of radiation frequencyLow costCompactness

Photonic generator of THz waveUsing 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 generationPhysical 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 project5. Our project

Thank you for your attention!