The New Passively Biased IFOG

A New Approach to IFOG by TeraEx Eliminating the phase modulator and its driver electronics Utilizing an innovative technique to passively bias the fiber coil Using non PM or standard fibers and components to reduce radiation sensitivity and cost Simplifying optics and electronics

A New Type of IFOG with Passively Biased Coil Sensor Coil Depolarizer SLED Detector Splitter Passively Biased Electronic Circuit Driver TeraEx IFOG makes use of property of depolarized light and further eliminates the problematic phase modulator and its associated driver electronics with a new passively biased optical coil residing in its quadrature point. A/D DSP Digital or Analog Signal Output AMP Quadrature point  Intensity

Advantages Of The New IFOG

Advantages of the New IFOG (no PM Fiber and Component) Sensor Coil Depolarizer SLED Detector Splitter Electronic Circuit A/D DSP Digital or Analog Signal Output AMP With TeraEx proprietary depolarized source the IFOG does not require PM fiber and components. This enables use of non radiation sensitive standard and low bending radius fiber for low cost and small coil size gyro’s respectively. Unlike PM, fiber length can be scaled up to many 10’s of km if needed.

Advantages of a Passive Type Bias Sensor Coil Depolarizer SLED Detector Splitter Electronic Circuit A/D DSP Digital or Analog Signal Output AMP In a vibration prone environment, the passive coil does not induce voltage noises or stress/thermal effects associated with active phase modulation. In addition electronics becomes simpler with no need for a modulator driver with its associated drifts. No induced noise voltage

Advantages of a Passive Type Bias…. Depolarizer SLED Detector Splitter Electronic Circuit A/D DSP Digital or Analog Signal Output AMP Length of fiber or size of fiber coil sensor can be freely chosen further simplifying the design of both optics and electronics. Miniature remote sensor coil with diameter of 0.5” or smaller is possible. Sensor Size

Advantages of a Passive Type Bias…. A passive single mode optical patch cord from meters to kilometers long connects the main module to its sensor head without any concern for noise pickups A tethered and passive remote sensor head can be placed anywhere in normal or harsh environment Sensor Coil Electronics can be placed in a controlled and safe environment far from the sensor head

Advantages of a Passive Type Bias…. The sensor head can also be connectorized with fiber optic bulkhead such as FC/PC

Advantages of a Passive Type Bias (3-D) A tethered and passive remote sensor head for sensing three axes of rotation simultaneously A passive single mode optical patch cord from meters to kilometers long connects the main module to its sensor head without any concern for noise pickups

No need for phase modulator and associated driver electronics No associated optical or electrical modulator drift No associated vibration noise generation (no PZT) No radiation or vacuum charge ups and drifts (no Lithium Niobate material) No fiber longevity concerns (PZT related) Unlike PM, fiber length can be scaled up to many 10’s of km if needed. Miniature remote sensor coil with diameter of 0.5” or smaller possible No associated noise pickups by tethered cable Any desired length tethered optical cable between remote sensor coil and its electronics No need for PM fiber and components and their associated radiation darkening Simpler optical and electronic circuitry In summary Advantages of TeraEx IFOG with Passive Bias are;

New Applications

With passive bias technology new applications would be opening up for IFOG. These applications may require sophisticated electronics in protected environment to meet high performance while necessitating miniature scale gyro probes for compact system integration capable of withstanding harsh conditions such as; High / low temperatures Oil drilling Wing of an airplane Under water cavern and deep sea scuba diving Satellite Condensed spaces Passive Bias Technology with Remote Sensor Head