Rotation measurement with the use of a pulsed Er-doped fiber laser with integrated optic circuit: Proposal, simple theory, and experiment

Abstract

We propose a noel pulsed fiber laser rotation sensor with a LiNbO integrated optic circuit, Sagnac fiber loop, Er-doped fiber, and 3 semiconductor pumping lasers. A simple analysis is completed and the output equation is deried. Theariance of the output pulse when rotation occurs is also analyzed. In addition, we also conducted a related experiment for rotation measurement. When the gain of the fiber ampli- fier is oer the round-trip loss and the phase modulation frequency satisfies the total round-trip time, this optical system produces the laser emission in a pulse state. The rotation rate is measured from the shift of the peak position of the output pulse. It is shown that the resolution of rotation measurement increases if we use a smaller phase modulation depth. But the sharpness of the optical pulse must be maintained by () reducing the losses or increasing the gain of optical amplifier in the whole optical system. Q 1997 John Wiley & Sons, Inc. Microwave Opt Technol Lett 15: 311)315, 1997. laser modes 6 . In this research we propose a novel fiber-optic rotation sensor with an integrated optic circuit, a Sagnac fiber loop, and an Er-doped fiber amplifier. This optical system produces a laser emission in the pulse state if the gain of fiber amplifier is greater than the whole round-trip transmis- sion loss, and if the frequency of phase modulator and the total loop length satisfy a certain mode-lock condition. The measurement of rotation rate is based on the peak shift of output pulse induced by the Sagnac effect.