Chengliang Yang

Novel NCF-FBG Interferometer for Simultaneous Measurement of Refractive Index and Temperature

A simple and compact interferometer structure based on no-core fiber (NCF) and fiber Bragg grating (FBG) is proposed for simultaneous measurement of surrounding refractive index (SRI) and temperature. Two methods of measurement may be used here: 1) the sensing information can be analyzed by the wavelengths shift of the NCF-based interferometer and one arbitrarily FBG-reflected modes, or 2) they can be solely extracted through both wavelength and power of each FBG reflected mode. Moreover, experimental results indicate that the SRI sensitivity of the FBG reflected core mode is up to 160.23 dB/RIU at a range from 1.3330 to 1.3780, which is the highest value to our knowledge.

Fiber Fault Detection With High Accuracy Using Chaotic Signal From an SOA Ring Reflectometry

A simple optical reflectometry with a semiconductor optical amplifier ring structure is proposed for the first time to locate the accurate fiber fault position using the chaotic correlation detection method. The experimental results show that a much higher spatial resolution of about 50 μm and a measured stability of ±150 μm are achieved.

Reconfigurable UWB Pulse Generation Based on Multi-Taps and a Programmable Filter

We propose a simple and new approach to generate the reconfigurable ultrawideband (UWB) pulse signal in optical domain. Phase modulation to intensity modulation conversion is utilized to obtain basic monocycle pulses with reversed polarity. Single mode fiber is adopted as dispersion media for introducing time delay between these monocycle pulses. By switching the taps coefficients, electrical monocycle, doublet, and triplet pulses can be obtained easily at the output of the photodetector. Experimental measurements in both time and frequency domains are presented.

Wavelength-swept single longitudinal mode fiber ring laser locked to 25 GHz ITU grid

Wavelength-swept single longitudinal mode fiber laser incorporating Fabry-Perot filter and bandpass filter is demonstrated. The proposed laser has a tuning range over 30 nm with tuning step 0.2 nm.

Multiwavelength generation based on a mode-locked fiber laser using carbon nanotube and fiber Fabry–Perot filter

In this paper, a novel and compact configuration of stable multiwavelength generation with a uniform wavelength interval is proposed for the first time to our knowledge. It employs a mode-locked fiber laser using a carbon nanotube and spectrum-slicing technique. A flat rectangular optical output spectrum is demonstrated by adjusting the dispersion value of the fiber-loop cavity and the pump power. With a fiber Fabry-Perot filter, 33 wavelengths with 0.2 nm spacing are obtained among the power uniformity of 2.3 dB. Moreover, the variations of output power at each wavelength are all less than 0.1 dB, which implies excellent stability of the whole structure.

Demonstration of low pulse repetition frequency erbium-doped fiber lasers

We demonstrate a low pulse repetition frequency (LPRF) Q-switched erbium-doped fiber (EDF) lasers based on acoustic optical modulator (AOM). The single wavelength fiber laser has a stable output at 1553 nm. In Q-switched operation, a pulse train with 3.3μs width and a repetition rate of 1kHz is obtained. The dual wavelength fiber laser is based on fiber Bragg gratings (FBGs) and a Faraday rotator mirror (FRM) as the laser cavity, which has a stable output at 1545 nm and 1557 nm with similar peak power and same repetition rate.

Multi-wavelength generation based on a mode-locked fiber laser using carbon nanotube and fiber Fabry-Perot filter

A novel configuration which employs a carbon nanotube (CNT) and spectrum-slicing technique for 33 wavelengths generation with 0.2 nm spacing among the power uniformity of 2.3 dB is proposed and demonstrated for the first time.