Ferrari department of engineering, university of cambridge, 9 jj thomson avenue, cambridge cb3 0fa, uk. Ultrafast lasers modelocked by nanotubes and graphene. Jan 27, 2016 femtosecond optical pulses have applications in optical communication, astronomical frequency combs and laser spectroscopy. It is shown that the modulation depth of the sa significantly affects the pulse duration at the laser output for a given cavity design mainly cavity dispersion and nonlinearity. Generally, these types of laser cavities provide typically pulses larger than those provided by a passively locked laser. Ultrafast stretchedpulse fiber laser modelocked by. Through synchronization of different transverse modes. Fiber lasers modelocked due to nonlinear polarization evolution npe may satisfy these. Using fast detection, we are able to observe the temporal and spectral evolutions of the breathers in real time. Modelocked ytterbium fiber laser tunable in the 9801070nm spectral range. With a single transverse mode, lasing occurs in longitudinal eigenmodes, which correspond to different patterns of the electromagnetic lasing field along the length of the fiber a, and resonant frequencies b.
The role of the saturable absorber in a modelocked fiber laser. We experimentally investigated the role of the saturable absorber sa in a mode locked fiber laser. The growing use of fiber lasers for this purpose is supported by customer demand for reliable femto and picosecond lasers with a long or, better, unlimited operation lifetime and without any need for manual adjustments. In actively mode locked fiber lasers, as shown in fig. Passively harmonic mode locking in ytterbiumdoped fiber laser with graphene oxide saturable absorber tions17 have been reported on the gsabased mode lock ing fiber laser emitting in different regions of wavelengths. We report on a midinfrared modelocked fiber laser that uses an acoustooptic tunable filter to achieve. Igor poberaj ljubljana, february 2011 abstract fiber lasers combine gain medium, resonator cavity and mirrors inside an optical fiber. Ultrafast stretchedpulse fiber laser modelocked by carbon. Rp photonics consulting on laser technology, nonlinear. Highpower modelocked 2 m multimode fiber laser request pdf. It is used for making pico and femtosecond soliton pulses. A group at air force research laboratory reported a fiber laser mode locked by multiple quantum well mqw saturable absorber with stable pulses generated as short as 2 ps 21. The pump power range associated with stable mode locking operation increases when the.
Introduction passively mode locked fiber lasers are attractive for many applications, such as optical communications 1, spectroscopy 2, and biomedical diagnostics 3, because of their simplicity, compactness, efficient heat. Numerical modelling is a powerful and wellproven tool for investigation of nonlinear polarization evolution npe modelocked fiber lasers, exhibiting various. Nathan kutz department of applied mathematics, university of washington, seattle, wa 981953925 abstractwe demonstrate that the integration of datadriven machine learning strategies with adaptive control are capable of producing an ef. Modelocked fiber laser based on chalcogenide microwires. Developing high energy mode locked fiber laser at 2 micron c. Kazakov 3, sergei turitsyn 1, aleksey rozhin 1 1aston institute of photonic technologies, aston university, aston triangle, birmingham, united kingdom, b4 7et. On modelling of npe modelocked fiber laser in presence of. Ultrafast lasers mode locked by nanotubes and graphene z. Liu school of electrical and electronic engineering, nanyang technological university, singapore abstract we report results of numerical simulations on the multiple soliton generation and soliton. An all fiber connected and polarization maintaining loop cavity of 500 m long is pumped by a linearly polarized 1120 nm yb fiber laser and modulated by an acoustooptic modulator. Passively synchronized qswitched and modelocked dual.
Nanotubes, fiber laser, saturable absorber, ultrafast pulse generation 1. Hybrid mode locked fiber ring laser using charcoal nanoparticles since the first demonstration of graphene saturable absorber for passively mode locked. Breathers introduce a new regime of mode locking into ultrafast lasers. Xu1,2 1key laboratory for laser plasmas ministry of education and department of physics. Breathing dissipative solitons in mode locked fiber lasers.
Modelocked fiber lasers with significant variability of generation. The results have shown the promise of using the mode locked fiber lasers to replace the bulk ultrashort pulse solidstate lasers for many practical applications. In a multimode fiber, the resonant frequency spectrum d and. Stability analysis of mode locked figureeight fiber laser m. Active mode locking of raman fiber laser is experimentally investigated for the first time. High noise is another problem for multi wavelength active mode locked fiber lasers. Modelocked femtosecond allnormal allpm ybdoped fiber laser at 1060nm article pdf available in optics communications 364. Stability analysis of mode locked figureeight fiber laser. While the quality remains high, so too does the level of power that the fiber laser beam delivers. Offering a wide spectrum of operating light wavelengths, durability of design and high wall.
The laser is self starting and the configuration is implementable as an all fiber laser with standard polarization. Here, a hybrid mode locked erbiumdoped fiber edf laser with. Modelocked fiber lasers with significant variability of. Pdf modelocked nddoped fiber laser at 930 nm researchgate. Fiber lasers exhibit inherent advantages of high gain coefficient, wide operating wavelength range, excellent heat dissipation, and robust mode confinement 31,32,33,34,35, and thus offer an attractive platform for testing the nonlinear absorption of the samples. Mechanism of multisoliton formation and soliton energy. Large normal dispersion modelocked erbiumdoped fiber laser. Introduction passively mode locked fiber lasers are attractive alternative to. Interesting facts about mode locked lasers mode locked lasers do not work 99. Our laser has successfully mode locked and stays mode locked untouched progressed autocorrelation technique for measuring ultrashort pulses conclusions. The dot of the fiber laser beam can be made incredibly small, perfect for applications such as laser cutting.
Erbium doped fiber laser mode locked by graphene in. Wavelength and pulse duration tunable ultrafast fiber. Erbium doped fiber laser mode locked by graphene in carboxymethylcellulose polymer composite chengbo mou 1, raz arif 1, anatoly s. A semiconductor mirror exhibiting only induced absorption is used to stabilize a ghz repetition rate active harmonically mode locked fiber laser, improving supermode. Large energy mode locking of an erbiumdoped fiber laser. Wavelength tunable performance of the mode locked fiber laser with the filter. Although mode locked diode lasers can be very compact and robust devices, which fit particularly well into optical fiber communications systems, they are subject to various limitations, which do not allow them to reach the full performance potential of, e. The typical spectrum of such a laser consists of a wide central peak and a few narrow lateral peaks that are placed symmetrically around it. Pdf we report on a passively modelocked neodymiumdoped oscillator featuring a wtype fiber operating at 930 nm. They exist in the laser cavity under the pump threshold of stationary mode locking. Laser built based on fiber technology developed for telecommunications have the potential to address these drawbacks.
The laser is based on a novel laser configuration that has negligible lowpower steadystate reflectivity from one side and, consequently, no cw gain. Zblan fiber lasers involve two separate cavities, one for each lasing wavelength, and a. Nonlinear polarization rotation for fiber lasers with ultrahigh pulse energy huiwen xu instructor. Modelocked fiber laser how is modelocked fiber laser. Mansoor sheikbahae abstract this report introduces principles of fiber lasers passively modelocked by nonlinear polarization rotation npr. Mechanism of multisoliton formation and soliton energy quantization in passively mode locked fiber lasers d. This concept opens up new degrees of freedom in the design of modelocked fiber lasers. Allfiber modelocked ultrafast thuliumdoped fiber lasers at 2 m. Modelocking is a technique in optics by which a laser can be made to produce pulses of light of extremely short duration, on the order of picoseconds 10. An environmentally stable mode locked fiber laser based on nonlinear polarization rotation is experimentally demonstrated. Pdf modelocked ytterbium fiber lasers lasse orsila. Dispersion and nonlinearity management of the laser cavity play an essential role. Nonlinear polarization rotation for fiber lasers with ultra. We report modelocking operation of a multimode thulium fiber laser at 2.
Conceptual outline of mode locked multimode fiber lasers. It has been observed that changes in the birefringence, which. The focus at nkt was further moved into applications of mode locked lasers at the collapse of the telecommunication market. Spatiotemporal mode locking in multimode fiber lasers. Furthermore, mode locked fiber lasers can rely on telecom components. Chu city university of hong kong, hongkong abstract mode locked. Pdf modelocked femtosecond allnormal allpm ybdoped. The mode locked fiber laser study performed in this thesis can be used to optimize the design and performance of mode locked fiber laser systems. Mode locked fiber lasers are widely used as sources of ultrashort optical pulses. Allfiber modelocked ultrafast thuliumdoped fiber lasers at 2 m qingqing wang, phd university of pittsburgh, 2014 in this work, we demonstrate three original all. Probability density functions pdf for rmsbandwidth see fig. The power of a fiber laser is constantly being improved and developed, and we now stock fiber lasers that have a power output over 6kw.
A figure8 laser is a fiber laser with a figure8shaped ring resonator. To do so, we built a passively modelocked fiber laser based on npr. Developing high energy modelocked fiber laser at 2 micron. Chapter 5 active mode locking forsimplicity, we assume, that the laser operates inthe transverse fundamental modes and, therefore, we only have to treat the longitudinal modes of the laser similar to a simple plane parallel fabryperot resonator figure. Abstractwe report the first modelocked, thuliumdoped fiber figureeight laser. A fiber pulsed laser with a 1cm cavity length and a 10ghz fundamental repetitionrate is demonstrated using a carbon nanotubebased mode locker deposited within the laser cavity. A technique for raising the possible pulse energy andor for lowering the pulse duration of a mode locked fiber laser is used in stretchedpulse fiber lasers 5, 8, 9, 19, 22, also sometimes called dispersionmanaged fiber lasers. This is the shortest fiber mode locked laser ever reported to date.
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