Gang-ding Peng - Academia.edu (original) (raw)

Papers by Gang-ding Peng

Optical Fiber Technology, 2011

Polymer fiber Bragg gratings (FBGs) are made using the modified sagnac system with a 355nm pulsed... more Polymer fiber Bragg gratings (FBGs) are made using the modified sagnac system with a 355nm pulsed laser from a photosensitive polymer optical fiber (POF) with external and core diameters of 290.6 and 21.0μm, respectively. Multimodes are reflected based on the reflection spectra of the gratings. The reflectivity spectra are also studied when such multimode polymer FBGs are subjected to axial

Optics Communications, 1998

In this analysis, we show that, using a Bragg grating in transmission mode, an optical filter bas... more In this analysis, we show that, using a Bragg grating in transmission mode, an optical filter based on an asymmetric twin-core fibre can operate with excellent narrow bandpass characteristics (e.g., pass bandwidths less than 1 nm) for optical wavelength division multiplexing systems. The grating in this scheme operates outside the band-gap. This ensures that the grating functions are in `transmission

Chinese Optics Letters, 2015

Photonics: Design, Technology, and Packaging, 2004

This paper reports on the scalability of MEMS optical cross-connect (OXC) switches which use 2D p... more This paper reports on the scalability of MEMS optical cross-connect (OXC) switches which use 2D planar waveguide architecture and an integrated waveguide lens to enhance free space propagation. The optical loss, total device area and ease of integration with MEMS micromirrors are considered for three competing layout configurations.

Optics Communications, 2006

Theoretical model for Er 3+ , Tm 3+ codoped fluoride fiber based on the rate and propagation equa... more Theoretical model for Er 3+ , Tm 3+ codoped fluoride fiber based on the rate and propagation equations has been established by considering the energy transfer process between Er 3+ and Tm 3+ , Er 3+ absorption in S-band as well as Tm 3+ absorption in C-band. The spectral gain as functions of the Er 3+ concentration, the fiber length, the pump power has been investigated. Two pumping schemes have been considered and compared with respect to their spectral gains. In the case of Er 3+ and Tm 3+ codoped fluoride fiber pumped by 0.15 W at 800 nm and 0.3 W at 1410 nm, a gain of 20 dB or more can be achieved in the range of 1450-1560 nm. The results show that significant S + C-band gain can be achieved by codoping Er 3+ in Tm 3+ doped fluoride fiber and using the dual-wavelength pumping scheme.

Advanced Sensor Systems and Applications II, 2005

This paper reports the development of a very compact and very-high sensitivity optical fibre hydr... more This paper reports the development of a very compact and very-high sensitivity optical fibre hydrophone system using a distributed-feedback fibre laser with a cavity length of 10cm. A theoretical system design making use of a Mach-Zehnder interferometer, homodyne demodulation scheme and digital signal processing is described. At the time of writing, the system is only partially completed; therefore the content of this paper will focus on the distributed-feedback fibre laser sensor head. Results for noise spectrum below 100kHz are presented, as well as discussions on some key issues with designing such hydrophone systems. Although not the intention for the system, initial results also indicate the suitability of the DFBFL for intensity modulated sensing.

Optics Letters, 2007

We propose a new multiplexing technique using amplitude-modulated chirped fiber Bragg gratings th... more We propose a new multiplexing technique using amplitude-modulated chirped fiber Bragg gratings that have an identical center Bragg wavelength. Each grating is inscribed with a unique amplitude modulation that allows them to be multiplexed with complete overlapping within a certain bandwidth. To demodulate the multiplexed signal, the discrete wavelet transform is employed. Concurrently, a wavelet denoising technique is used to reduce the noise. This proposed multiplexing technique has been verified through strain

Optoelectronics Letters, 2005

A theoretical model is developed for the laser-diode-pumped Tm 3+ -doped fiber amplifier,and a se... more A theoretical model is developed for the laser-diode-pumped Tm 3+ -doped fiber amplifier,and a set of ordinary differential equations (ODEs) governing the dynamics of dual-wavelength pumping scheme (]. 4 pm+ 1.56 lam) based on the rate equations and propagation equations was established. The relationship between the spectra gain and pump power was described and analyzed by numerically solving the ODEs. Spectral gain as a function of longitudinal position along the fiber was given to optimize the fiber length~ spectral gain per unit length,and fractional inversion were used to explain the gain shift property of TDFA. The theoretical results agree well with the experimental data. CLC number:TN253 Document code.A Article ID:1673ID: -1905ID: (200501-0033-04

Measurement Science & Technology, 2008

An in-line in-fibre ring cavity is fabricated by writing two blazed gratings in the one fibre to ... more An in-line in-fibre ring cavity is fabricated by writing two blazed gratings in the one fibre to form a Fabry-Perot cavity. Interference is set up between an injected guided mode and a ring mode formed by light scattered by the gratings from the core mode to a reverse propagating ghost mode and then back into the original core mode again.

We demonstrate mode-division multiplexed transmission using the LP01 and LP11 modes over three he... more We demonstrate mode-division multiplexed transmission using the LP01 and LP11 modes over three heterogeneous spans of few-mode fiber and investigate the impact of fusion splicing and free-space coupling on mode mixing.

Photonic Sensors, 2011

We report our recent work on distributed feedback fiber laser based hydrophones. Some issues rela... more We report our recent work on distributed feedback fiber laser based hydrophones. Some issues related to sensitivity, such as fiber laser phase condition, demodulation, and packaging, are also discussed. With the development of appropriate digital signal processing (DSP) techniques and packaging designs, an interferometric-type distributed feedback (DFB) fiber laser hydrophone system with acoustic sensitivity of 58.0 dB·re·μPa·Hz −0.5 at 1 kHz or a minimum detectable acoustic pressure below 800 μPa during field test is attained. We have also investigated an intensity-type DFB fiber laser hydrophone system and its performance.

Optoelectronics Letters, 2007

Page 1. A distributed polarization-mode coupling measurement system was designed and implemented ... more Page 1. A distributed polarization-mode coupling measurement system was designed and implemented using white light interferometry. It can be used for the measurement of polarization mode coupling in a high-birefringence fiber of up to 1 km. ...

SUMMARY Monitoring structural response induced by seismic waves is an efficient way to mitigate t... more SUMMARY Monitoring structural response induced by seismic waves is an efficient way to mitigate the damage of earthquakes. For example, the measured signal can be used to activate an alarm system in order to evacuate people from an endangered building, or to drive a control system to suppress earthquake-excited vibrations so as to protect the integrity of the structure, or

Monitoring the response of structures, especially tall buildings, under severe loading conditions... more Monitoring the response of structures, especially tall buildings, under severe loading conditions is an important requirement for the validation of their design and construction, as well as being a maintenance concern. Traditionally such response has been measured using accelerometers. However it is impossible to measure the static or quasi-static components of movement with such sensors. An integrated system comprising RTK-GPS, accelerometer, and optical fiber sensors has been proposed for monitoring structural deformation, with the objective being to assess the integrity of structures. The GPS and accelerometer sensors have been installed on a 108m tall steel tower in Tokyo, together with other sensors such as anemometer and strain gauge. In this paper the seismic and wind-induced responses of the tower are analysed using Fast Fourier Transformation (FFT) of the GPS and accelerometer measurements. Then the correlated signals are extracted by a digital filtering technique. The filt...

Optics Letters, 2006

We propose a demodulation technique for a multiplexed fiber Fizeau interferometer (FFI) and fiber... more We propose a demodulation technique for a multiplexed fiber Fizeau interferometer (FFI) and fiber Bragg grating (FBG) sensor system using the discrete wavelet transform with signal processing enhancements. This simple and flexible demodulation technique determines the cavity length of FFI and the Bragg wavelength of FBG simultaneously and is especially suited for quasi-static measurements. We demonstrate this demodulation technique by performing some strain measurements, and a strain resolution of 1.0 microepsilon and an accuracy of 2.6 microepsilon are obtained. The maximum cross-talk of the sensor system is 6% of the applied strains.

Optics Letters, 2010

We report writing polymer optical fiber (POF) gratings in photosensitive POFs doped with benzildi... more We report writing polymer optical fiber (POF) gratings in photosensitive POFs doped with benzildimethylketal (BDK) (BPOF in short) using a 355 nm laser for what we believe to be the first time. Both multimode and single-mode FBGs were fabricated with relatively low writing intensity. The enhanced photosensitivity of the doped POFs is also evident by the observation of obvious change in the UV-visible absorption.

Optics Express, 2005

We propose a novel scheme in which Yb3+ codoping and a laser cavity are introduced in Tm3+ doped ... more We propose a novel scheme in which Yb3+ codoping and a laser cavity are introduced in Tm3+ doped fiber to achieve efficient S-band optical amplification with a 980 nm pump source. This scheme makes it possible for conventional 980 nm pump sources for Er3+ doped fiber amplifiers to be used for S-band Tm3+ doped fiber amplifiers (TDFAs). By introducing a laser cavity into an amplifier, an internally generated pump from Yb3+ at a desirable wavelength for pumping Tm3+ could be produced. We establish and analyze, for the first time to our knowledge, a new theoretical model that takes into consideration both the internal lasing operation inside the optical amplification process and the energy transfer between the Tm3+ and the Yb3+ ions in TDFAs. Various situations such as Tm3+ doping concentration and cavity reflectivity have been investigated. The results show that high optical gain and high pump efficiency can be achieved by use of 980 nm sources. With a laser cavity of 1050 nm in Tm3+ and Yb3+ codoped fiber, for example, it is possible to achieve high optical gain of greater than 20 dB, a noise figure of approximately 5 dB in the wavelength range from 1450 to 1480 nm with a 0.3 W power at 980 nm pump source.

Optics Express, 2013

The spectral characteristics of four different types of apodized fiber Bragg gratings with a sing... more The spectral characteristics of four different types of apodized fiber Bragg gratings with a single π phase shift are analyzed based on the simulation. The 2-discrete Gaussian apodization is proved to have the most effective suppression to grating side mode. A novel asymmetrical distributed feedback fiber laser based on this apodization structure is presented and fabricated as well. The grating has a -20 dB side-mode suppression. The laser exhibits a high power ratio of backward to forward outputs. It has a relative intensity noise of -90 dB/Hz and a linewidth of 20k Hz operating in a single polarization longitudinal mode.

Optics Communications, 2000

An improvement has been made to Rouard's method for the analysis of fiber and waveguide ... more An improvement has been made to Rouard's method for the analysis of fiber and waveguide gratings. The real reflectivity of each interface is used instead of an approximate value obtained by coupled-mode theory. The improved Rouard's method becomes a complete Rouard's method and an exact method. It is simple and independent on coupled-mode theory for no calculation of coupling coefficient required. Numerical examples of uniform and nonuniform gratings have been given.

Optics Communications, 2009

Based on the photoinduced birefringence in azo materials, the model of the birefringent long peri... more Based on the photoinduced birefringence in azo materials, the model of the birefringent long period fiber gratings (BLPFGs) has been proposed and the transmission of such birefringent fiber gratings was further simulated by the coupled mode theory. In order to obtain the optimum condition for making birefringent azopolymer optical fiber (APOF) gratings the photoinduced birefringence of azo dye and methyl methacrylate (MMA) copolymers was systematically studied. After photosensitivity study of azo samples, using Teflon technique, azo dye containing single mode polymer optical fiber (POF) was fabricated. Finally, BLPFGs can be fabricated in azopolymer fiber using polarized 532 nm laser. A 120 lm LPFG with a 50% duty cycle has been successfully written within the core of the fiber with 532 nm laser by an amplitude mask method. Under polarized microphotography, the grating was observed when the optical axis was set at 45°with the direction of the first polarizing lens of the polarization microscope.