US 5,353,262 A · Optical transducer and method of use

Abstract

An optical transducer, such as used in an ultrasound system, includes a signal laser which generates an optical signal the frequency of which varies in correspondence with acoustic energy incident on the transducer. An optical cavity in the signal laser is disposed such that incident acoustic energy causes compression and rarefaction of the optical cavity, and this displacement varies optical frequency generated by the laser. A laser pump coupled to the lasing medium is adapted to apply selected levels of excitation energy appropriate to the generation and detection of acoustic pulses. The signal laser alternatively is adapted such that the refractive index of the optical cavity is varied in correspondence with the incident acoustic energy to modulate the optical frequency of the light generated by the signal laser. A piezoelectric device is disposed to receive the incident acoustic energy and generate a corresponding electrical signal that is applied to an electro-optic cell in the optical cavity, or alternatively, to conductors to generate an electric field across the lasing medium.

Claims45

Dependent claims

An optical transducer for detecting acoustic energy propagated through a medium, the transducer comprising:

a transducer housing, and
a signal laser mounted in said transducer housing,
said signal laser comprising a single optical cavity having an optical path axis, a lasing medium disposed in said optical cavity, and first and second reflectors, said first and second reflectors being respectively disposed immediately adjacent to opposite ends of said lasing medium along said optical path axis such that a single lasing output signal is generated by said signal laser, the optical frequency of said single lasing output signal being modulable in correspondence with acoustic energy incident on said transducer.

An optical transducer for detecting acoustic energy propagated through a medium, the transducer comprising:

a transducer housing,
a signal laser mounted in said transducer housing,
a laser pump optically coupled to said optical cavity, said laser pump being adapted to provide a selectable level of excitation energy to said lasing medium;
said signal laser further comprising an optical cavity having an optical path axis;
a lasing medium disposed in said optical cavity;
a first reflector, said first reflector being disposed at a first end surface of said optical cavity;
and a compliant cavity optically coupled to a second end surface of said optical cavity, said second end surface being disposed opposite said first end surface;
said compliant cavity further comprising a partially transmissive reflector, a compliant medium, and a high reflectance reflector, said partially transmissive reflector being optically coupled to said second end surface of said optical cavity, said compliant medium being disposed between and optically coupled to said partially transmissive reflector and said high reflectance reflector such that a single lasing output signal is generated by said signal laser, the optical frequency of said single lasing output signals generated by said signal laser being modulable in correspondence with acoustic energy incident on said transducer;
said compliant medium being adapted to be responsive to a selected transmit-level excitation energy so as to selectively generate an acoustic pulse.

6 more elements

Dependencies are inferred from the claim text.

Optical transducer and method of use

Life of this patent

Optical transducer and method of use

Life of this patent

Abstract

Claims45