Claims
- 1. A propagation measuring apparatus for measuring propagation characteristics of an object to be measured comprising:
a first light source for outputting a first optical signal of a first frequency; a second light source for outputting a second optical signal of a second frequency; a terahertz light outputting unit for generating terahertz light of a frequency, which is equal to a difference between said first and second frequencies, by using said first and second optical signals and radiating said terahertz light to said object to be measured; a first detecting unit for detecting said terahertz light passing through said object to be measured; and a measuring unit for measuring said propagation characteristics of said object to be measured based on said terahertz light detected by said first detecting unit.
- 2. A propagation measuring apparatus as claimed in claim 1, wherein said first and second light sources output said first and second optical signals of infrared light respectively.
- 3. A propagation measuring apparatus as claimed in claim 1 further comprising:
a reference signal source for generating a reference signal; and a modulating unit for modulating at least one of said first and second optical signals based on said reference signal generated by said reference signal source, wherein said measuring unit measures said propagation characteristics of said object to be measured based on at least one of said first and second optical signals modulated by said modulating unit and said reference signal generated by said reference signal source.
- 4. A propagation measuring apparatus as claimed in claim 3, wherein said modulating unit modulates intensity of said first optical signal outputted by said first light source, and
said terahertz light outputting unit generates said terahertz light by using said first optical signal of which said intensity is modulated by said modulating unit and said second optical signal outputted by said second light source and radiates said terahertz light to said object to be measured.
- 5. A propagation measuring apparatus as claimed in claim 3 further comprising a first multiplexer for multiplexing said first optical signal generated by said first light source and said second optical signal generated by said second light source,
wherein said modulating unit modulates intensities of said first and second optical signals multiplexed by said first multiplexer, and said terahertz light outputting unit generates said terahertz light by using said first and second optical signals of which said intensities is modulated by said modulating unit and radiates said terahertz light to said object to be measured.
- 6. A propagation measuring apparatus as claimed in claim 1 further comprising a second detecting unit for said terahertz light radiated by said terahertz light outputting unit not through said object to be measured,
wherein said measuring unit measures said propagation characteristics of said object to be measured based on said terahertz light detected by said first and second detecting units.
- 7. A propagation measuring apparatus as claimed in claim 3 further comprising:
a first demultiplexer for demultiplexing said first optical signal outputted by said first light source; a second demultiplexer for demultiplexing said second optical signal outputted by said second light source; a first multiplexer for multiplexing a first component of said first optical signal demultiplexed by said first demultiplexer and a first component of said second optical signal demultiplexed by said second demultiplexer; and a second multiplexer for multiplexing a second component of said first optical signal demultiplexed by said first demultiplexer and a second component of said second optical signal demultiplexed by said second demultiplexer, wherein said terahertz light outputting unit generates said terahertz light by using said first and second optical signals multiplexed by said first multiplexer and radiates said terahertz light to said object to be measured, said modulating unit modulates a frequency of said second component of said first optical signal demultiplexed by said first demultiplexer, said second multiplexer multiplexes said second component of said first optical signal of which said frequency is modulated by said modulating unit and said second component of said second optical signal demultiplexed by said second demultiplexer, and said first detecting unit performs heterodyne detection of said terahertz light passing through said object to be measured by using said second components of said first and second optical signals multiplexed by said second multiplexer.
- 8. A propagation measuring apparatus as claimed in claim 7 further comprising a delay element for delaying at least one of said second component of said first optical signal demultiplexed by said first demultiplexer and said second component of said second optical signal demultiplexed by said second demultiplexer.
- 9. A propagation measuring apparatus as claimed in claim 7 further comprising a second detecting unit for detecting said terahertz light radiated by said terahertz light outputting unit not through said object to be measured and performing heterodyne detection by using said second components of said first and second optical signals multiplexed by said second multiplexer,
wherein said measuring unit measures said propagation characteristics of said object to be measured based on results of said heterodyne detection of said first and second detecting units.
- 10. A propagation measuring apparatus as claimed in claim 3, wherein said modulating unit is an optical intensity modulator, optical frequency converter or acousto-optic converter.
- 11. A propagation measuring apparatus as claimed in claim 1, wherein said difference between said first and second frequencies is within a range of 100 GHz to 10 THz, and
said terahertz light outputting unit generates terahertz light of 100 GHz to 10 THz and radiates said terahertz light to said object to be measured.
- 12. A propagation measuring apparatus as claimed in claim 1, wherein said first or second light source sweeps frequency and outputs said first or second optical signal.
- 13. A propagation measuring apparatus as claimed in claim 1, wherein said first and second light sources output said first and second optical signals of continuous light.
- 14. A propagation measuring method for measuring propagation characteristics of an object to be measured comprising:
a first output step of outputting a first optical signal of a first frequency; a second output step of outputting a second optical signal of a second frequency; a terahertz light output step of generating terahertz light of a frequency, which is equal to a difference between said first and second frequencies, by using said first and second optical signals and radiating said object to be measured; a first detection step of detecting said terahertz light passing through said object to be measured; and a measurement step of measuring said propagation characteristics of said object to be measured based on said terahertz light detected in said first detection step.
- 15. A propagation measuring method as claimed in claim 14 further comprising:
a reference signal generation step of generating a reference signal; and a modulation step of modulating at least one of said first and second optical signals based on said reference signal generated in said reference signal generation step, wherein said measurement step comprises a step of measuring said propagation characteristics of said object to be measured based on at least one of said first and second optical signals modulated in said modulation step and said reference signal generated in said reference signal.
- 16. A propagation measuring method as claimed in claim 14 further comprising a second detection step of detecting said terahertz light radiated in said terahertz light output step not through said object to be measured,
wherein said measurement step comprises a step of measuring said propagation characteristics of said object to be measured based on said terahertz light detected in said first and second detection steps.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2001-200377 |
Jul 2001 |
JP |
|
Parent Case Info
[0001] The present application is a continuation application of PCT/JP02/06175 filed on Jun. 20, 2002 which claims priority from a Japanese patent application No. 2001-200377 filed on Jul. 2, 2001, the entire contents of which are incorporated herein by reference.
Continuations (1)
|
Number |
Date |
Country |
Parent |
PCT/JP02/06175 |
Jun 2002 |
US |
Child |
10740999 |
Dec 2003 |
US |