1989 Fiscal Year Final Research Report Summary
WIDEBAND TUNABLE OPTICAL AMPLIFIER BY MEANS OF NONLINEAR OPTICAL SUSCEPTIBILITIES
| Project/Area Number |
62460134
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
電子機器工学
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| Research Institution | Nagaoka University of Technology |
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Principal Investigator |
SAKUDA Kyohei Nagaoka Univ. of Tech., Electrical Eng. Dept, professor., 工学部, 教授 (60143814)
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| Co-Investigator(Kenkyū-buntansha) |
KAMBAYASHI Toshio Nagaoka Univ. of Tech., Electrical Eng. Dept, Assistant Professor., 工学部, 助教授 (20111669)
IIDA Seishi Nagaoka Univ. of Tech., Electrical Eng. Dept, Professor, 工学部, 教授 (90126467)
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| Project Period (FY) |
1987 – 1989
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| Keywords | Semiconductor optical amplifier / Distributed feedback optical amplifier / Refractive index grating / Nonlinear optics |
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| Research Abstract |
Laser diodes (LD) have been used as optical amplifiers in optoelectronics. Recently, amplification characteristics of distributed feedback (DFB) laser amplifiers are reported.
In this report a new type of an optical amplifier using gallium arsenide (GaAs) laser diode is proposed. This amplifier has the following advantages:
(1) narrow bandwidth like a DFB laser amplifier.
(2) a wide tuning range of amplification wavelength with high gain.
Because of tunablility realized by a refractive index grating, this proposed amplifier behaves like a DFB reflector. This refractive index is generated by photoexcitation due to two incident beaus (interference fringes). A period of the interference fringes, i.e. a grating period, is varied by changing an angle of the two incident beams. Therefore amplification wavelength which is determined by the Bragg's law is tunable in a wide range.
The report contains the following contents: first, principles of the refractive index changes in GaAs are discussed. The refractive index change can be realized by dispersion effects on absorption edges and explained by nonlinear susceptibilities. Secondly, experimental results are reported. AlGaAs CSP laser diodes with cleaved facets are used in this experiment.
Two different wavelengths are chosen for the interference incident beams, When the interference beams are incident, the spectra of the amplifiers are investigated by a monochrometer.
As a result, when Ar laser (wavelength is 514.5nm which is clos; to the second absorption edge) is used as the incident beams, the distributed feedback effects are observed. But, for more accurate quantitative experiments, the amplifier needs to be higher durability in addition to higher precision optical equipment.
Amplification characteristics of DFB amplifier have been investigated, hence these results in this report show a possibility of a wideband optical amplifier.
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