Open Loop Fiber Optic Gyroscope : A Technical Note

  • M.H. Khan Hindustan Aeronautics Limited. Korwa
  • C. Ramakrishna Institute of Armament Technology, Pune.
Keywords: Fiber couplers, PINFET detector, Gyro transfer function, Interferometric fiber optic gyroscope


This technical note describes the design and fabrication of a prototype open-loop interferometric fiber-optic gyroscope (IFOG). The gyro transfer function is transposed from that of a raised-cosine to a sine function using AC modulation, giving maximum sensitivity at rest. Among various signal processing methods, lock-in principle is used to detect the Sagnac phase shift due to rotation. Initial work is done with bulk-optic components. Finally, all-fiber gyroscope is built using laser diode (1300 nm), PINFET detector, fiber couplers and PZT phase modulator. An effort is made to develop compact IFOG with sensing coil diameter of 10 cm and signal processing card of size 10 x 6.5 sq cm. The present set-up is able to detect the direction of rotation at a rotation rate of 5 x 10/sup -4/ radian per second. Presently, the performance of the set-up is limited by the difficulty in achieving complete reciprocity.

Author Biographies

M.H. Khan, Hindustan Aeronautics Limited. Korwa
Shri M H Khan completed his BE (Electronics & Communication) from University of Roorkee in 1983 and joined Hindustan Aeronautics Limited. He, completed his MTech\ (Lasers & Electrooptics) from Institute of Armament Technology, Pune in 1,993 and Diploma in Manage'!1ent from Indira Gandhi National Open University, New Delhi, in 1994. Presenbly, he is working in Design Department as Manager (Design). The areas of his interest are r~ng laser and fibre-optic gyros.
C. Ramakrishna, Institute of Armament Technology, Pune.
Pror C Ramakrlshna received his MSc in Physics in 1962 from Sri Venkaleswara University, Tirupati. Laler, he received his MTech in Lasers & Electrooptics from the Uniiversity of Poona, in 1990. Presently, he is Professor at the Faculty of Applied Physics, Institule of Armament
Technology, Pune. His recent interests Include: fiber-optics, carbondioxide lazers, semiconductor lasers, laser communication and semiconductor diode-pumped ND:YAG lasers.
How to Cite
Khan, M., & Ramakrishna, C. (2013). Open Loop Fiber Optic Gyroscope : A Technical Note. Defence Science Journal, 46(4), 283-288.
Electronics & Communication Systems

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