Oguz ÇELIKEL^* and Sait Eren SAN¹

TUBITAK (Ulusal Metroloji Enstitüsü) UME Optics Laboratory, Fiber Optic Metrology Division, P.O. Box 54, 41470 Gebze-Kocaeli, Turkey
¹Department of Physics, Gebze Institute of Technology (GYTE), 41400 Gebze-Kocaeli, Turkey

(Received September 8, 2008; Accepted October 22, 2008; Revised October 21, 2008)

This paper describes the design details and the characterization of an all digital closed-loop (ADCL) interferometric fiber optic gyroscope (IFOG) Prototype with sine wave biasing modulation and SLED emiting at 1288.9 nm, constructed in TUBITAK UME. Electronic feedback section of ADCL-IFOG is composed of 16 bit AD7714YN ADC, 14 bit-LTC1667CG DAC, fully controlled and synchronized by 89C51 microcontroller. The averaged sensitivity of the ADCL-IFOG prototype in unit of error voltage applied to the phase modulator was calculated as 132.65 μV/(^°/h) which equals to a scale factor of 7.53888 (^°/h)/mV with a standard deviation of 0.85% for a range of 1–15270 (^°/h) rotation rate, corresponding to a range of Sagnac phase shifts varying from 0.00115 to 17.57448 (^°). The maximum peak to peak noise and the bias stability of the prototype were determined as 4.97 and 1.48 (^°/h) at 23.0 °C, respectively. The variation of the noise and bias stability on a temperature range of 23.0–42.0 °C was observed.

Key words: all digital closed-loop IFOG, open-loop IFOG, Sagnac phase, SLED, scale factor, bias modulation

^*E-mail address: oguz.celikel@ume.tubitak.gov.tr