Dual-wavelength Distributed Feedback Fiber Laser Research Articles

Experimental study on dual-wavelength distributed feedback fiber laser

Four distributed feedback fiber lasers with dual-wavelength operations were studied experimentally in detail. The laser characteristics of these distributed feedback fiber lasers (DFB-FLs) were investigated. The operation conditions for the dual-wavelength output are analyzed and presented. Through this study, the guidance of the design and fabrication of some dual-wavelength distributed feedback fiber lasers are provided.

Dual-wavelength DFB Fiber Laser based Equivalent Phase Shift

Abstract A new structured dual-wavelength distributed feedback fiber laser is proposed. In this new structure, phase shift is introduced as well as equivalent phase shift. Theoretical analysis and simulation demonstrates this new structure is able to provide separate resonant cavities to overcome mode competition. Different channels of sampled fiber Bragg gratings are utilized simultaneously, so wide wavelength spacing could be achieved. A 31 GHz spaced dual-wavelength DFB fiber laser is achieved on an Er-doped fiber with excimer laser and homogeneous phase plate. Experiments shows that dual-wavelength lasing is achieved and laser power is in reverse proportion with coupling coefficient of the FBG.

A novel dual-wavelength DFB fiber laser

A new structured dual-wavelength distributed feedback fiber laser is proposed. In this new structure, phase shift is introduced as well as equivalent phase shift. Theoretical analysis and simulation demonstrate that this new structure is able to provide separate resonant cavities to overcome mode competition. Different channels of sampled fiber Bragg gratings are utilized simultaneously, so that wide wavelength spacing could be achieved. A 31GHz spaced dual-wavelength DFB fiber laser is achieved on an erbium-doped fiber with excimer laser and homogeneous phase plate. Experiments show that dual-wavelength lasing is achieved and laser power is in reverse proportion with coupling coefficient of the FBG.

Design of multiwavelength DFB fiber laser with equivalent phase shifts

A dual-wavelength distributed feedback fiber laser with two equivalent phase shifts is proposed and demonstrated experimentally. By studying varied parameters of the fiber laser, which show different impacts on the lasers' characteristic, a dual-wavelength laser of 31 pm spacing is designed and fabricated. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1453–1456, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25969

Dual-wavelength distributed feedback fiber laser based on double exposure and equivalent phase shift method

A special sampling structure based on double exposure technology is proposed to achieve dual-wavelength lasing in the distributed feedback fiber laser. This structure is composed of two grating pitches in one sampling period, which could be realized by changing the fiber's length in the fabrication. Through employing an equivalent phase shift, only a submicrometer-level precision is required for precise phase control. Then a stable dual-wavelength laser with the spacing of 400 pm is obtained in the experiment successfully. The output power is 30.46 μW and the sidemode suppression ratio is 46 dB under a pumped power of 146 mW.

A dual wavelength distributed-feedback fiber laser

An approach to accessing air holes in a structured optical fiber with a distributed-feedback (DFB) laser based on higher order mode lasing is proposed and demonstrated. A narrow linewidth DFB fiber laser is fabricated in rare-earth-doped structured optical fiber. A higher order mode is shown to lase. Dual laser operation in both fundamental and higher order modes is also achieved. Numerical simulation of the mode profiles within the fiber using the adjustable boundary conditions-Fourier decomposition method supports the experimental results. Laser performance for each mode is characterized including imaging the emission of pump and lasing mode intensity profiles.

A Novel Dual-Wavelength DFB Fiber Laser Based on Symmetrical FBG Structure

A novel grating structure is proposed and demonstrated to obtain stable dual-wavelength (DW) distributed-feedback (DFB) fiber lasers at room temperature. The proposed grating is based on a symmetrical structure, where one half is periodically sampled by "0"-to-"pi" period and the other half is done by "pi"-to-"0" period. This structure can create two separated resonance cavities and hence achieve the stable DW lasing operation. By fabricating the proposed grating on a piece of Er : Yb-codoped fiber, we experimentally obtain a stable DW-DFB fiber laser with wavelength spacing of ~440 pm at room temperature

Stable Dual-Wavelength DFB Fiber Laser With Separate Resonant Cavities and Its Application in Tunable Microwave Generation

A single-longitudinal-mode dual-wavelength distributed feedback fiber laser with a wavelength spacing of 0.312 nm is proposed and demonstrated. Based on two spatially separated resonant cavities in a single fiber Bragg grating made by a simple method, stable dual-wavelength lasing is established. Then, a 38.67-GHz microwave signal generated by beating the two lasing wavelengths is obtained with a 3-dB bandwidth of ~6 kHz and a frequency drift <5 MHz without any feedback mechanism. As a potential application of this device, a tunable microwave source ranging from 18.67 to 58.67 GHz (with a small discontinuity) is proposed and partially demonstrated

Dual-Wavelength DFB Fiber Laser Based on Unequalized Phase Shifts

A novel structure for dual-wavelength distributed feedback (DFB) fiber laser is proposed and experimentally demonstrated. This structure is based on a uniform fiber Bragg grating with two unequalized phase shifts, which markedly suppress the mode competition of the two lasing wavelengths; and then a 52-pm-spaced dual-wavelength DFB fiber laser operating at single-longitudinal-mode and single-polarization is achieved at room temperature. A simple method is also implemented to fabricate the phase shifts with high precision

Dual-Wavelength DFB Fiber Laser Based on a Chirped Structure and the Equivalent Phase Shift Method

A chirped phase-shifted structure is demonstrated for compact multiwavelength distributed feedback (DFB) fiber laser at room temperature for the first time. The chirped structure provides separated resonance cavities and then the stable multiwavelength operation. The equivalent phase shift method is demonstrated to realize the desired chirp and phase shifts simply and flexibly. A 44-pm-spaced dual-wavelength DFB fiber laser is then achieved experimentally, which is the narrowest spacing ever reported for a compact multiwavelength fiber laser