In this article, a novel approach for demodulation of fiber grating sensors with high resolution is proposed based on a hybrid fiber optical bistablity device (OBD). This OBD is consisted of a FFP ring-cavity laser, fiber Bragg grating (FBG) and a certain optoelectronic feedback circuit. The optical bistability can be realized through alternative the center wavelength of the tunable fiber laser when the output power of the laser is fixed. The Bragg wavelength of sensing grating is determined by the switching on voltage of OBD.
In this article, a novel technique of fiber sensor demodulation for fiber Michelson interferometric sensor is proposed. The
output optical signal of the interferometric sensor is processed by a hybrid optical bistable device in frequency domain.
When the optical path difference between the two arms of the sensor changing, it will cause the bistable device switching
on and switching off. The measurement is realized by counting the optoelectronic pulses. The experimental and
simulation results show that this technique with high accuracy, the resolution of the length measurement is nanometer
Proc. SPIE. 6595, Fundamental Problems of Optoelectronics and Microelectronics III
KEYWORDS: Digital signal processing, Fiber Bragg gratings, Sensors, Field programmable gate arrays, Control systems, Demodulation, Signal processing, Charge-coupled devices, Data conversion, CCD image sensors
In this paper, we present a novel design of spectral detection circuit for demodulating fiber Bragg grating (FBG). New
type field programmable gate array (FPGA) has been used to make the circuit more compact. We use NIOS-II operating
system in FPGA to deal with the real-time data measurement, so needn't any extra micro-programmed control unit
(MCU) and other processing electronic devices. The circuit system in this paper, including the charge coupled device
(CCD) driver, signal processing, analog-digital conversion and processing of optoelectronic image data, can be widely
used in FBG sensor field.
In this paper, we propose a novel scheme of fiber Bragg grating interrogation by use of hybrid fiber optical bistable
device (OBD). The OBD is realized in the fiber Bragg grating (FBG) sensing element. Light source is an electronic tuned
widely swept ring fiber laser. In this experiment, FBG's are acting as optical intensity modulator and sensing elements at
same time. Combined with feedback control circuit, the OBD can be used as an optic-fiber sensor working in digital type
through bistable switching phenomenon. We discuss the mechanism of this bistable sensor. Scanning the bias Voltage on
PZT, the bistable pulse signal can be counted by circuit that operates in the manner of a pulse-equivalent. If we use 16 bit
Digital Analog Converter (DAC), the resolution will achieve 1pm level. High accuracy, high speed and high ratio of
signal to noise are the advantages of this scheme.
In this paper the properties of phase conjugation of KNSBN:C crystal are studied. XOR and ANDlogic operation are
accomplished with the erasable property of SPPC and the reversible property of ISPPC. The all-optical half-adder is
realized by integrating them. For the first time to our knowledge they combined with the mutual reading property of
MPPC to realize the all-optical full-adder.