Fiber optic transducers, fiber optic accelerometers and fiber optic sensing systems

A transducer comprising:

• a fixed portion configured to be secured to a body of interest;
• a moveable portion having a range of motion with respect to the fixed portion;
• a spring positioned between the fixed portion and the moveable portion;
• and
• a length of fiber wound between the fixed portion and the moveable portion, the length of fiber spanning the spring,
• wherein the fixed portion, the moveable portion, and the spring are formed from a unitary piece of material.

An accelerometer comprising:

• a fixed portion configured to be secured to a body of interest;
• a moveable portion having a range of motion with respect to the fixed portion;
• a spring positioned between the fixed portion and the moveable portion;
• a length of fiber wound between the fixed portion and the moveable portion, the length of fiber spanning the spring;
• and
• a mass engaged with the moveable portion, such that the mass envelopes the moveable portion.

An accelerometer comprising:

• (a) a transducer including (1) a fixed portion configured to be secured to a body of interest, (2) a moveable portion having a range of motion with respect to the fixed portion, (3) a spring positioned between the fixed portion and the moveable portion, and (4) a mass engaged with the moveable portion;
• (b) a length of fiber including a portion wound between the fixed portion and the moveable portion, the portion spanning the spring;
• (c) a reflector positioned along the length of fiber;
• (d) an optical source for transmitting an optical signal along the length of fiber to the reflector;
• (e) a fiber optic coupler for splitting the optical signal from the optical source into at least two separate optical signals, and for recombining the at least two separate optical signals into a combined optical signal;
• (f) an optical receiver for receiving the combined optical signal, wherein at least one of the reflector and the fiber optic coupler is housed within the mass.

An accelerometer comprising:

• a fixed portion configured to be secured to a body of interest;
• a moveable portion having a range of motion with respect to the fixed portion;
• a spring positioned between the fixed portion and the moveable portion;
• and
• a length of fiber wound between the fixed portion and the moveable portion, the length of fiber spanning the spring,
• wherein the fixed portion, the moveable portion, and the spring are formed from a unitary piece of material.

A fiber optic sensing system comprising:

• an optical source for generating an optical signal;
• an optical element for dividing the optical signal generated by the optical source, and for coherently recombining optical signals received by the optical element;
• an optical receiver for receiving a combined optical signal downstream of the optical element;
• a transducer including (1) a fixed portion configured to be secured to a body of interest, (2) a moveable portion having a range of motion with respect to the fixed portion, (3) a spring positioned between the fixed portion and the moveable portion, and a mass engaged with the moveable portion, with the mass enveloping the moveable portion;
• and
• optical fiber extending between elements of the fiber optic sensing system, the optical fiber including a length of fiber wound between the fixed portion and the moveable portion, and the length of fiber spanning the spring.

A fiber optic sensing system comprising:

• an optical source for generating an optical signal;
• an optical element for dividing the optical signal generated by the optical source, and for recombining optical signals received by the optical element;
• an optical receiver for receiving a combined optical signal downstream of the optical element;
• a transducer including (1) a fixed portion configured to be secured to a body of interest, (2) a moveable portion having a range of motion with respect to the fixed portion, (3) a spring positioned between the fixed portion and the moveable portion, and (4) a mass engaged with the moveable portion;
• fiber optic cable extending between elements of the fiber optic sensing system, the fiber optic cable including a length of fiber wound between the fixed portion and the moveable portion, the length of fiber spanning the spring;
• and
• a reflector positioned along the fiber optic cable,
• wherein at least one of the reflector and the optical element is housed within the mass.

A fiber optic sensing system comprising:

• an optical source for generating an optical signal;
• an optical element for dividing the optical signal generated by the optical source, and for recombining optical signals received by the optical element;
• an optical receiver for receiving a combined optical signal downstream of the optical element;
• a transducer including (1) a fixed portion configured to be secured to a body of interest, (2) a moveable portion having a range of motion with respect to the fixed portion, and (3) a spring positioned between the fixed portion and the moveable portion, wherein the fixed portion, the moveable portion, and the spring are formed from a unitary piece of material;
• and
• fiber optic cable extending between elements of the fiber optic sensing system, the fiber optic cable including a length of fiber wound between the fixed portion and the moveable portion, the length of fiber spanning the spring.