All-fiber Chirped Pulse Amplification System Research Articles

High-Power GHz Burst-Mode All-Fiber Laser System with Sub 300 fs Pulse Duration

An all-fiber low-repetition-rate SESAM mode-locked fiber oscillator combined with a dispersion-managed active fiber loop produces a flexible GHz burst-mode laser source. The high-power output is then produced by amplifying the GHz burst-mode laser source using an all-fiber chirped-pulse amplification system. Then, the laser is compressed using a grating pair compressor; a maximum amplified power of 97 W is obtained. This results in a compressed high power of 82.07 W with a power stability RMS of 0.09% and beam quality better than 1.2. Accurate dispersion control allows for the production of a high-quality pulse duration of 265 fs.

A large dispersion-managed monolithic all-fiber chirped pulse amplification system for high-energy femtosecond laser generation

A high energy monolithic all fiber chirped pulse amplification (CPA) system composed of fiber-silicate glass fiber is demonstrated in this work. In this compact system, the optical stretcher consists of two large dispersion chirped fiber Bragg gratings that offer a high stretch ratio to lower the nonlinearity that accumulates in the fiber amplifier. By employing high gain silicate glass fiber with a length of 20 cm as the main amplifier, an optimal balance of pulse energy and the B-integral is achieved. An amplified power of 42.6 W, corresponding to a pulse energy of 213 µJ, is obtained with an injection power of 100 mW. After compression, the laser pulses are compressed by a novel polarization-controlled double-pass configuration of a chirped volume Bragg grating (CVBG) to match the dispersion of the fiber stretcher. A total compression efficiency of 79.8% is obtained. The dispersion between the stretcher and the compressor is matched with the self-made temperature tuning device of the fiber grating. An optimized pulse width of 781 fs and a pulse energy of 170 µJ are obtained with the single-mode beam profile. To the best of our knowledge, this is the highest energy ever obtained with a single-mode beam profile for a spliced monolithic all-fiber CPA system. This compact high-energy fiber system will be useful in scientific research and industrial applications.

50 μJ Femtosecond Laser System Based on Strictly All-Fiber CPA Structure

We demonstrate a strictly all-polarization maintaining, all-fiber chirped pulse amplification of ultrashort pulses. Pulses with the duration of 933 fs and energy as high as 50 μJ are achieved at 200 kHz repetition rate in a compact size. The variations of the spectra and pulse widths as functions of the amplified output power have also been presented. To our best knowledge, this is the highest energy extracted from the strictly all-fiber chirped pulse amplification system. The environmentally stable femtosecond laser source will find various applications in practice.

High-Peak-Power Ultrashort Pulse Generation Using All-Fiber Chirped Pulse Amplification System with Small Core Multimode Fiber

We present an all-fiber chirped pulse amplification system based on a normally dispersive single mode Er-doped fiber and a multimode fiber of 25 µm core diameter. The 260 fs sech2 transform-limited pulses generated in a passively mode-locked Er-doped fiber laser are stretched to 1 ps and amplified in an Er-doped fiber amplifier. Then the subsequent multimode fiber in which the pulses propagate only in the fundamental mode compresses the pulses to 80 fs. The pulse compression using the conventional multimode fiber as a large-core single-mode fiber is demonstrated for the first time. The peak power of the output pulses is increased to 44 kW.

Slicing the supercontinuum radiation generated in photonic crystal fiber using an all-fiber chirped-pulse amplification system

We report on an experimental study of supercontinuum broadening in photonic crystal fiber performed by measuring the temporal behavior of spectrally-sliced radiation in different propagation regimes. The study confirms the soliton fission theory by observing the red-shifted fundamental solitons and blue-shifted nonsolitonic radiation.

An optimized Er gain band all-fiber chirped pulse amplification system

We demonstrate an all-fiber Er chirped pulse amplification (CPA) system based on compression in photonic band gap fiber (PBGF) that produces 570 fs pulses with 312 nJ pulse energy. The dispersion of the PBGF is measured precisely and used to design a dispersion-matched nonlinearly-chirped fiber Bragg grating stretcher. We analyze the trade-offs of such all-fiber CPA system design and compare different PBGFs in terms of the derived figure of merit. Such system architecture should be scalable to few micro-Joule level pulse energies close to the compressor nonlinearity limit when PBGFs with improved figure of merit become available.

Femtosecond pulse amplification in cladding-pumped fibers

Femtosecond pulse amplification in a cladding-pumped fiber amplifier is demonstrated for the first time to our knowledge. Using a cladding-pumped erbium-doped fiber power amplifier and a passively mode-locked fiber seed oscillator in conjunction with an all-fiber chirped-pulse amplification system, we obtain 380-fs near-bandwidth-limited pulses with an average power of 260 mW. The pulse repetition rate is varied between 5 and 50 MHz, and pulse energies as high as 20 nJ are generated.