Browsing by Subject "Peak power"
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Item Open Access All-fiber high-energy yb-doped fiber amplifier(IEEE, 2009) Öktem, Bülent; Kalaycioǧlu, Hamit; İlday, F. ÖmerWe report a robust, all-fiber amplifier seeded by a fiber oscillator. Seed pulses at 1 MHz repetition rate are amplified up to 3 μJ, delivering 1 μJ-energy, 170 fs-long pulses. Duration reduces to 120 fs at 1 μJ amplifier output. These are the highest peak powers from an integrated fiber source. © 2009 IEEE.Item Open Access Doping management for high-power fiber lasers: 100 W, few-picosecond pulse generation from an all-fiber-integrated amplifier(Optical Society of America, 2012-07-16) Elahi, P.; Yilmaz, S.; Akçaalan, Ö.; Kalaycioğlu, H.; Öktem, B.; Şenel, Ç.; Ilday, F. Ö.; Eken, K.Thermal effects, which limit the average power, can be minimized by using low-doped, longer gain fibers, whereas the presence of nonlinear effects requires use of high-doped, shorter fibers to maximize the peak power. We propose the use of varying doping levels along the gain fiber to circumvent these opposing requirements. By analogy to dispersion management and nonlinearity management, we refer to this scheme as doping management. As a practical first implementation, we report on the development of a fiber laser-amplifier system, the last stage of which has a hybrid gain fiber composed of high-doped and low-doped Yb fibers. The amplifier generates 100 W at 100 MHz with pulse energy of 1 μJ. The seed source is a passively mode-locked fiber oscillator operating in the all-normaldispersion regime. The amplifier comprises three stages, which are all-fiber-integrated, delivering 13 ps pulses at full power. By optionally placing a grating compressor after the first stage amplifier, chirp of the seed pulses can be controlled, which allows an extra degree of freedom in the interplay between dispersion and self-phase modulation. This way, the laser delivers 4.5 ps pulses with ∼200 kW peak power directly from fiber, without using external pulse compression.Item Open Access Femtosecond microjoule-Class ytterbium fiber lasers(Optical Society of America, 2011) Lecaplain, C.; Ortaç, Bülend; Machinet G.; Boullet J.; Baumgartl, M.; Schreiber, T.; Cormier, E.; Hideur, A.We report the generation of 830 nJ energy from a mode-locked all-normal dispersion fiber laser featuring large-mode-area photonic crystal fibers. After external compression, 550 fs pulses with 1.2 MW peak power are demonstrated. © 2011 OSA.Item Open Access Femtosecond pulse generation from an extended cavity Cr4+: Forsterite laser using graphene on YAG(Optical Society of America, 2013) Baylam I.; Ozharar, S.; Natali Cizmeciyan, M.; Balcı, Osman; Pince, Erçağ; Kocabaş, Coşkun; Sennaroglu, A.A room temperature, multipass-cavity, femtosecond Cr4+:forsterite laser was modelocked with a single-layer graphene saturable absorber on a YAG substrate. The resonator produced nearly transform-limited 92 fs pulses near 1250 nm with 53 kW of peak power. © OSA 2013.Item Open Access High average and peak power femtosecond large-pitch photonic-crystal-fiber laser(2011) Baumgartl, M.; Jansen F.; Stutzki F.; Jauregui, C.; Ortaç, B.; Limpert J.; Tünnermann, A.We report on the generation of high-average-power and high-peak-power ultrashort pulses from a mode-locked fiber laser operating in the all-normal-dispersion regime. As gain medium, a large-mode-area ytterbium-doped large-pitch photonic-crystal fiber is used. The self-starting fiber laser delivers 27 W of average power at 50:57 MHz repetition rate, resulting in 534 nJ of pulse energy. The laser produces positively chirped 2 ps output pulses, which are compressed down to sub-100 fs, leading to pulse peak powers as high as 3:2 MW. © 2011 Optical Society of America.Item Open Access High-energy femtosecond photonic crystal fiber laser(2010) Lecaplain, C.; Ortaç, B.; MacHinet G.; Boullet J.; Baumgart, M.; Schreiber, T.; Cormier, E.; Hideur, A.We report the generation of high-energy high-peak power pulses in an all-normal dispersion fiber laser featuring large-mode-area photonic crystal fibers. The self-starting chirped-pulse fiber oscillator delivers 11 W of average power at 15:5 MHz repetition rate, resulting in 710 nJ of pulse energy. The output pulses are dechirped outside the cavity from 7 ps to nearly transform-limited duration of 300 fs, leading to pulse peak powers as high as 1:9 MW. Numerical simulations reveal that pulse shaping is dominated by the amplitude modulation and spectral filtering provided by a resonant semiconductor saturable absorber. © 2010 Optical Society of America.Item Open Access Microjoule pulse energies at 1 MHz repetition rate from an all-fiber nonlinear chirped-pulse amplifier(Optical Society of America, 2010) Kalaycioǧlu H.; Oktem, B.; Ömer Ilday F.We report a 1-MHz robust, all-fiber amplifier-oscillator system. Amplified pulses of 3 μJ are externally compressed to 140 fs. The highest peak power from an integrated fiber source, up to 50 kW, is obtained. © 2010 Optical Society of America.Item Open Access Microjoule-energy, 1 MHz repetition rate pulses from all-fiber-integrated nonlinear chirped-pulse amplifier(Optical Society of America, 2010-03-23) Kalaycioglu, H.; Oktem, B.; Şenel, Ç.; Paltani, P. P.; Ilday, F. Ö.We demonstrate generation of pulses with up to 4 μJ energy at 1 MHz repetition rate through nonlinear chirped-pulse amplification in an entirely fiber-integrated amplifier, seeded by a fiber oscillator. The peak power and the estimated nonlinear phase shift of the amplified pulses are as much as 57 kW and 22π, respectively. The shortest compressed pulse duration of 140 fs is obtained for 3.1 μJ of uncompressed amplifier output energy at 18 π of nonlinear phase shift. At 4 μJ of energy, the nonlinear phase shift is 22 π and compression leads to 170-fs-long pulses. Numerical simulations are utilized to model the experiments and identify the limitations. Amplification is ultimately limited by the onset of Raman amplification of the longer edge of the spectrum with an uncompressible phase profile.Item Open Access Sub-80 fe dissipative soliton large-mode-area fiber laser(2010) Baumgartl, M.; Ortaç, B.; Lecaplain, C.; Hideur, A.; Limpert J.; Tünnermann, A.We report on high-energy ultrashort pulse generation from an all-normal-dispersion large-mode-area fiber laser by exploiting an efficient combination of nonlinear polarization evolution (NPE) and a semiconductor-based saturable absorber mode-locking mechanism. The watt-level laser directly emits chirped pulses with a duration of 1 ps and 163 nJ of pulse energy. These can be compressed to 77 fs, generating megawatt-level peak power. Intracavity dynamics are discussed by numerical simulation, and the intracavity pulse evolution reveals that NPE plays a key role in pulse shaping. © 2010 Optical Society of America.Item Open Access Theoretical analysis of doping management(IEEE, 2013) Gürsel, A. T.; Elahi, Parviz; İlday, F. Ömer; Ozyazici, M.S.Two opposing requirements, such as thermal load and nonlinear effects are important limitations in rapid progress of high-power fiber laser technologies. Thermal effects, which limit the average power, can be minimized by using low-doped, longer gain fibers, whereas presence of nonlinear effects requires use of high-doped, shorter fibers to maximize the peak power. Proposed solution of the problem is the use of varying doping levels along the gain fiber to circumvent to mitigate the trade-off between thermal load and nonlinear effects. © 2013 The Chamber of Turkish Electrical Engineers-Bursa.