Communications – electrical: acoustic wave systems and devices – Signal transducers – Underwater type
Patent
1995-04-03
1997-06-03
Lobo, Ian J.
Communications, electrical: acoustic wave systems and devices
Signal transducers
Underwater type
73657, 356349, 356351, H04R 2300, G01B 902
Patent
active
056361815
ABSTRACT:
An ultrasound/vibration sensor consisting of a microchip laser or an array of microchip lasers constructed to oscillate at two different laser frequencies corresponding to two orthogonal polarizations is disclosed. The frequency difference between these two modes is chosen to be within the bandwidth of an electrical (as opposed to optical) signal processing system. When the microchip laser or microchip laser array is placed in an acoustic field, its cavity length is modulated which causes a frequency modulation of the frequency difference between the two modes. When the two laser output polarizations are mixed using a polarization scrambling device such as a polarizer at about 45 degrees to the polarization axes and then detected with a photodiode, one for each microchip laser, the resulting electrical signal contains the FM modulated beat frequency between the two polarization modes. This is then demodulated using an electrical signal processing system.
REFERENCES:
patent: 3808557 (1974-04-01), Smiley
patent: 4449825 (1984-05-01), May
patent: 5353262 (1994-10-01), Yakymyshyn et al.
"Stress-Induced Tuning of a Diode-Laser-Excited Monolithic Nd:YAG Laser," Adelbert Owyoung; Peter Esherick, Optics Letters, vol. 12, No. 12, Dec., 1987, pp. 999-1001.
"Diode-Pumped Microchip Lasers Electro-Optically Q Switched at High Pulse Repetition Rates," JJ Zayhowski; C. Dill III, Optics Letters, vol. 17, No. 17, Sep., 1992, pp. 1201-1203.
"Polarization-Switchable Microchip Lasers," JJ Zayhowski, Appl. Phys. Lett. 58(24), 17 Jun., 1991, pp. 2746-2748.
"High-Resolution Force Sensing by a Diode-Pumped Nd:YAG Laser," Wolfgang Holzapfel, Martin Finnemann, Optics Letters, vol. 23, No. 18, Dec., 1993, pp. 2062-2064.
General Electric Company
Lobo Ian J.
Pittman William H.
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