Multiwavelength Actively Mode-locked Fiber Laser with a Double-ring Configuration and Integrated Cascaded Sampled Fiber Bragg Gratings

A modified multiwavelength actively mode-locked fiber ring laser is proposed and experimentally demonstrated. In this kind of laser, stable multiwavelengths lasing is achieved by integrating cascaded sampled fiber Bragg gratings(SFBGs) into the laser cavity. To implement actively mode-locking technique, a double-ring cavity configuration is used to assure that the cavity lengths for all wavelengths lasing are identical. Thus, simultaneous mode locking of all wavelengths has been successfully achieved by using the same mode-locking signal.

Dynamic OADM Using Tunable Sampled Bragg Gratings Based on Vernier Effect

A novel dynamic optical add-drop multiplexer(OADM) scheme using tunable sampled fiber Bragg gratings(SFBG) by Vernier effect is firstly proposed. In this scheme, broad wavelength tuning range is achieved by only slightly adjusting the SFBG, the wavelength tuning of OADM will be faster than traditional dynamic OADM.

Analysis of Sampled Fiber Bragg Grating Based on the Photonic Crystal Theory

One of the most basic characteristics of photonic crystal is frequency band gap. When defects are introduced into the periodic photonic crystal, a number of defect modes appear in the stop band. In this paper, we exploit transfer matrix method based on photonic crystal theory, and assume the sampled fiber Bragg grating as one-dimensional dual photonic crystal with a large size defect. Characteristics of the sampled fiber Bragg grating are analyzed. Experimental results show that the sampled fiber Bragg grating has many reflective peaks. Its reflectivity, center wavelength, reflective peak intervals and band width all change with the grating parameters, including grating length, duty ratio of the material with high dielectric constant, and index modulation depth and period. Results agree with the conventional couple mode theory which can be used when analyzing other characteristics of the sampled fiber Bragg grating or applying it into practice.

Drawing Tower In-Line Fabrication and the Spectrum Analysis of Sampled Fiber Grating

Sampled fiber grating is a special superstructure fiber Bragg grating with a wide range of applications in many fields.In this work,based on drawing tower in-line fabrication system,a new preparation method of the sampled fiber grating is proposed and experimentally demonstrated.Experimental result shows that the obtained sampled fiber gratings possess dense reflection spectra,with a minimum reflection peak interval of only 0.09 nm.This method exhibits promising application prospect in the fabrication of the high-quality sampled fiber grating.On the other hand,the spectral characteristics of the sampled fiber grating are analyzed when the sub-grating is affected by the external physical quantities such as,in this paper,strain.Wavelength shift and intensity change in the reflection peak of the spectra indicate that the grating is affected differently by micro strains,due to the different spatial positions along the axis of the sampled fiber grating.This work is aimed at exploring the potential applications of the sampled fiber grating in quasi-distributed micro-area sensing with the millimeter level.