High Power Linearly Polarized Fiber Lasers in a Linear Cavity

10.32920/ryerson.14657970 ◽

2021 ◽

Author(s):

Angie Reda Abdelhay Mohamed Ali Eldamak

Keyword(s):

Theoretical Model ◽

Fiber Laser ◽

High Power ◽

Fiber Lasers ◽

Mode Locking ◽

Gain Medium ◽

The Self ◽

Pulse Envelope ◽

Linear Cavity ◽

Linearly Polarized

This thesis presents two designs for high power linearly polarized all-fiber linear cavity lasers, continuous wave (CW) and mode-locked. The cavity designs use Polarization Maintaining (PM) fibers for both gain medium and Fiber Bragg Gratings (FBGs). The FBG pairs select lasing wavelength and polarization. The fiber lasers incorporating specialty designed FBGs achieve an extinction ratio larger than 23 dB. Firstly, an all-fiber linear cavity design of a high power picoseconds mode-locked laser is introduced. The proposed configuration is based on Non-Linear Polarization (NPR) using PM Yb-doped active fiber and two matching FBGs to form the laser cavity. The combination of nonlinearity, gain and birefringence in cavity made the laser generate mode-locked pulses in picoseconds range and with high average output power. The output mode-locked pulses amplitude is modulated with an envelope whose mechanism is also investigated in this thesis project. Experimental data and numerical simulations of the self mode-locking fiber laser are presented. Main parameters affecting mode-locked pulses and its envelope are identified. In addition, a new theoretical model based on Nonlinear Schrödinger Equation (NLSE) is developed and implemented on the MATLAB platform. The model explains the self mode-locking mechanism and the source of the pulse envelope. In this model, it is proven that self phase modulation (SPM) plays an essential role in pulse formation and shaping. The theoretical model and experimental results are in a very good agreement at different pumping levels. A method of regulating the mode-locked pulses is presented. This is achieved by applying a pulsed current to pump diode. This method successfully stabilizes the mode-locked pulses underneath a Q-switched pulse envelope. Further scale-up of average power and pulse energy is realized by adding an amplifier stage. Secondly, a CW dual-wavelength all-fiber laser is presented. The laser consists of two pairs of FBGs and a PM Er/Yb co-doped fiber as a gain medium. The laser emits at both 1 μm and 1.5 μm wavelengths simultaneously with a stable output. This laser provides a compact fiber-based pumping source that is suitable for mid-IR generation.

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Chip-Scale, High Power Microstructure Fiber Laser

MRS Proceedings ◽

10.1557/proc-883-ff2.1 ◽

2005 ◽

Vol 883 ◽

Author(s):

Nasser Peyghambarian ◽

Axel Schülzgen ◽

Masud Mansuripur ◽

Jerome V. Moloney ◽

Tiequn Qiu ◽

...

Keyword(s):

Fiber Laser ◽

High Power ◽

Fiber Lasers ◽

Mode Locking ◽

Single Frequency ◽

Microstructured Fibers ◽

Microstructure Fiber ◽

Cw Operation ◽

Spectral Linewidth ◽

Q Switching

AbstractCompact, robust, high power fiber lasers have been demonstrated. In fiber lasers of only a few cm length we obtained up to 10 W of cw output power, diffraction limited beam profiles at 4 W cw operation, 1.6 W output with single frequency operation, and more than 150 mW output with a spectral linewidth of a few kHz. The potential of active microstructured fibers for further improvements in fiber laser performance has been shown. We also demonstrated Q-switching and mode-locking of these compact fiber lasers.

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Development of fiber laser optic system for laser polishing of parts

Science intensive technologies in mechanical engineering ◽

10.12737/21235 ◽

2016 ◽

Vol 1 (9) ◽

pp. 16-23 ◽

Cited By ~ 1

Author(s):

Александр Савкин ◽

Aleksandr Savkin ◽

Владислав Фунтиков ◽

Vladislav Funtikov ◽

Александр Григорьянц ◽

...

Keyword(s):

Stainless Steel ◽

Fiber Laser ◽

High Power ◽

Fiber Lasers ◽

Sample Surface ◽

Optic System ◽

Laser Polishing ◽

Approximate Description ◽

Laser Head ◽

Laser Optic

The possibility of an approximate description of a multimode beam of a fiber laser in the Zemax modeling system for the development of an optic system of a laser head is shown. There are developed and manufactured optic units of a laser head taking into account characteristic peculiarities of radiation of high-power fiber lasers. The possibilities are shown the developed optic system in the technology of laser polishing by the remelting of a sample surface made of stainless steel of type 1540-00.

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Investigation on extreme frequency shift in silica fiber-based high-power Raman fiber laser

High Power Laser Science and Engineering ◽

10.1017/hpl.2018.22 ◽

2018 ◽

Vol 6 ◽

Cited By ~ 6

Author(s):

Jiaxin Song ◽

Hanshuo Wu ◽

Jun Ye ◽

Hanwei Zhang ◽

Jiangming Xu ◽

...

Keyword(s):

Frequency Shift ◽

Fiber Laser ◽

High Power ◽

High Efficiency ◽

Maximum Output Power ◽

Gain Medium ◽

Maximum Output ◽

Optical Efficiency ◽

Central Wavelength ◽

Raman Fiber Laser

In this paper, we experimentally investigated the extreme frequency shift in high-power Raman fiber laser (RFL). The RFL was developed by using a pair of fiber Bragg gratings with fixed and matched central wavelength (1120 nm) combined with a piece of 31-m-long polarization maintaining (PM) passive fiber adopted as Raman gain medium. The pump source was a homemade high-power, linearly polarized (LP) wavelength-tunable master oscillator power amplifier (MOPA) source with ${\sim}25~\text{nm}$ tunable working range (1055–1080 nm). High-power and high-efficiency RFL with extreme frequency shift between the pump and Stokes light was explored. It is found that frequency shift located within 10.6 THz and 15.2 THz can ensure efficient Raman lasing, where the conversion efficiency is more than 95% of the maximal value, 71.3%. In addition, a maximum output power of 147.1 W was obtained with an optical efficiency of 71.3%, which is the highest power ever reported in LP RFLs to the best of our knowledge.

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