| Project/Area Number |
60550022
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
物理計測・光学
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| Research Institution | Osaka University |
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Principal Investigator |
SAKAI Kiyomi Faculty of Engineering, Osaka University/Assistant Prof., 工学部, 助手 (00029109)
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| Project Period (FY) |
1985 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1987: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1986: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1985: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | Submm waves / Nb SIS / Heterodyning / Mixer / Optically pumped submm laser / Frequency stabilization / 受信器 / NbSIS |
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| Research Abstract |
For the development of the submm heterodyne spectroscopy, the investigations of submm local oscillators and the low noise mixers are importnat.
1. Local oscillators (LO's) To stabilize the power and the frequency of the CO_2 pumped submm laser, which is almost only choice for the submm heterodyne LO's we have developed two methods of CO_2 laser stabilization which is the key for the purpose; (1) A technique to lock the pump frequency to the Lamp dip of the submm laser gas with the aid of the Stark modulation, (2) A method to lock the pump frequency using an external two-beam interferometer of which path length is controlled with a He-Ne Zeeman laser. An frequency stabilization of the order of 10^<-8> was obtained by these methods.
2. Mixers (1) The Nb point-contact Josephson junctions were constructed in a form of a 4 wavelength (4<gamma>) long-wire antenna and a corner erflector. A SSB mixer noise temperature of 1660K and a conversion efficiency of -16.8 dB were estimated at 639 GHz (469 <micrn>). (2) The SIS junctions of Pb alloy having a long-wire antenna were fabricated. Some experiments of harmonic mixing were made using the mixers. The conversion loss of 43.5 dB were obtained for the 5th harmonic mixing between 693 GHz and 139 GHz, for example. (3)The Nb SIS mixers with 4 junctions in series and with a printed bow-tie antenna, was fabricated and they were mounted in a quasi-optical beam guide. An experiment of fundamental mixing was carrierd out at 337 GHz. It was confirmed that the mixing based on the quasi-particle was done.
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