Ultrashort-pulse fiber ring lasers

Abstract

Abstract. This paper reviews recent progress on ultrashort pulse generation with erbium-doped fiber ring lasers. The passive mode-locking technique of polarization additive pulse mode-locking (P-APM) is used to generate stable, selfstarting, sub-500 fs pulses at the fundamental repetition rate from a unidirectional fiber ring laser operating in the soliton regime. Saturation of the APM, spectral sideband generation, and intracavity filtering are discussed. Harmonic modelocking of fiber ring lasers with soliton pulse compression is addressed, and stability regions for the solitons are mapped and compared with theoretical predictions. The stretchedpulse laser, which incorporates segments of positive-and negative-dispersion fiber into the P-APM fiber ring, generates shorter (sub-100 fs) pulses with broader bandwidths (> 65 nm) and higher pulse energies (up to 2.7 nJ). We discuss optimization of the net dispersion of the stretched-pulse laser, use of the APM rejection port as the laser output port, and frequency doubling for amplifier seed applications. We also review the analytical theory of the stretched-pulse laser as well as discuss the excellent noise characteristics of both the soliton and stretched-pulse lasers. 42.60F; 42.65; 42.80 Fiber lasers were made possible in the 1960s by the incorporation of trivalent rare-earth ions such as neodymium, erbium, and thulium into glass hosts [1]. Soon thereafter neodymium was incorporated into the cores of fiber waveguides [2,3]. Due to the high efficiency of the Nd +3 ion as a laser, early work focused on Nd +3 -doped silica fiber lasers operating at 1.06 µm [4]. Doping of silica fibers with Er +3 ions was not achieved until the 1980s [5,6]. Since that time Er +3 -doped fiber lasers have received much attention, because the lasing wavelength at 1.55 µm falls within the low-loss window of optical fibers and thus is suitable for optical fiber communications. Rare-earth ions such as Ho +3 [7,8], Tm +3 [9-11], and * Current address: Lucent Technologies/Bell Labs, 791 Holmdel-Keyport Road, Holmdel, NJ, USA * * Current address: NTT Access Network Systems Laboratory, Tokai-mura, Naka-gun, Ibaraki-ken 319-11, Japan Yb +3 [12,13] have also been used as dopants or co-dopants in silica or fluoride fibers, allowing new lasing or pumping wavelengths, and Pr +3 has been incorporated into fluoride fiber, providing emission at 1.3 µm [14,15]. PACS:Among the numerous advantages of fiber lasers are simple doping procedures, low loss, and the possibility of pumping with compact, efficient diodes. The fiber itself provides the waveguide, and the availability of various fiber components minimizes the need for bulk optics and mechanical alignment. Many different cavity configurations can be easily built with fibers and fused-fiber couplers, including linear FabryPerot, ring, and combinations of the two. Enhancement of the fiber nonlinearity due to large signal intensities and long interaction lengths is an additional advantage of fiber lasers that is particularly important for mode-locki...

Few-cycle pulses from a graphene mode-locked all-fiber laser

“…A strategy to overcome these limitations in all-fiber laser formats is to use a dispersion-managed design [40,41], where alternating segments of positive (or normal) and negative (or anomalous) dispersion fibers lead to periodic broadening and compression of the intracavity pulses [40,41]. Compared to soliton mode-locking, the average ∆τ can increase by an order of magnitude or more, which significantly reduces the intracavity P peak , thus being less susceptible to nonlinear optical effects [40,41]. However, in all-fiber oscillators, it is difficult to achieve the minimum ∆τ , as set by T 0 .…”

“…For our seed oscillator, we design a dispersion-managed soliton [26], able to generate shorter ∆τ with broader ∆λ than soliton lasers [41], schematically presented in Fig.2(a). The total cavity length is L c ∼11m.…”

Testing the Stability of the Fine Structure Constant in the Laboratory

“…Another class of frequency combs that can stay in lock for longer times are fs fiber lasers (Nelson et al 1997). The most common type is the erbium doped fiber laser that emits within the telecom band around 1550 nm.…”

Stability calculations for the ytterbium-doped fibre laser passively mode-locked through nonlinear polarization rotation

“…In this paper we are interested in mode-locking through nonlinear polarization rotation. This technique has been successfully used to obtain short pulse generation in different rare-earth doped fiber lasers [3]- [5], [12]- [15] and is self-starting. The laser configuration is a unidirectional fiber ring cavity containing a polarizer placed between two polarization controllers.…”