2.4 GHz L-band passively harmonic mode locked Er-doped fiber laser based on carbon nanotubes film

We experimentally demonstrate a passively harmonic mode locked (PHML) Er-doped fiber laser with pump power efficiency up to 17 MHz/mW operating at L-band based on single walled carbon nanotubes polyvinyl alcohol (SWCNTs-PVA) film. Under 233 mW pump power, the stable pulse train at 1594.97 nm with 40.5 dB side mode suppression ratio (SMSR) and 742 fs pulse duration is obtained at a repetition rate of 1.923 GHz, corresponding to 170th harmonic of the fundamental frequency. Under optimized intracavity conditions, the pulses frequency is able to scale up to 2.415 GHz with a high level of 40 dB SMSR, which to the best of our knowledge, is the highest value yet reported from a L-band PHML fiber laser incorporating SWCNTs as saturable absorber (SA). Such high repetition rate and stable fiber laser operating at L band may be desirable for various applications

Passively harmonic mode-locking in an Erbium-doped fiber laser based on carbon nanotubes film at repetition rates to 500MHz

Passively harmonic mode-locking (HML) of an Erbium-doped fiber laser using carbon nanotubes polyvinyl alcohol (CNTs-PVA) film is presented. The 20th harmonic mode-locking pulses at 500MHz repetition rate with 42dB super-mode suppression ratio (SMSR) are achieved

Observation of 550 MHz passively harmonic mode-locked pulses at L-band in an Er-doped fiber laser using carbon nanotubes film

We demonstrate a passively harmonic mode-locked (PHML) fiber laser operating at the L-band using carbon nanotubes polyvinyl alcohol (CNTs-PVA) film. Under suitable pump power and an appropriate setting of the polarization controller (PC), the 54th harmonic pulses at the L-band are generated with the side mode suppression ratio (SMSR) better than 44 dB and a repetition frequency of 503.37 MHz. Further increasing the pump power leads to a higher frequency of 550 MHz with compromised stability of 38.5 dB SMSR. To the best of our knowledge, this is the first demonstration on the generation of L-band PHML pulses from an Er-doped fiber laser based on CNTs

Passively harmonic mode-locked erbium-doped fiber laser at a 580 MHz repetition rate based on carbon nanotubes film

We propose and demonstrate a passively harmonic mode-locked erbium-doped fiber laser (EDFL) using carbon nanotubes polyvinyl alcohol (CNTs-PVA) film. The laser allows generation of the pulses with a repetition rate of 580 MHz, which corresponds to the 22nd harmonics of a 26.3 MHz fundamental repetition rate under 323 mW pump power. A particularly noteworthy feature of the pulses is the super-mode suppression ratio (SMSR), which is over 40 dB, indicating a stable operation

Passively harmonic mode-locked erbium-doped fiber laser at a 580 MHz repetition rate based on carbon nanotubes film

We propose and demonstrate a passively harmonic mode-locked erbium-doped fiber laser (EDFL) using carbon nanotubes polyvinyl alcohol (CNTs-PVA) film. The laser allows generation of the pulses with a repetition rate of 580 MHz, which corresponds to the 22nd harmonics of a 26.3 MHz fundamental repetition rate under 323 mW pump power. A particularly noteworthy feature of the pulses is the super-mode suppression ratio (SMSR), which is over 40 dB, indicating a stable operation

Influence of average cavity dispersion and spectral bandwidth on passively harmonic mode locked L-band Er-doped fiber laser

We systematically study the impact of average cavity dispersion and pulse spectral bandwidth on harmonic mode locking in the long-wavelength band from an Er-doped fiber laser using carbon nanotubes polyvinyl alcohol (CNTs-PVA) film mode locker. By carrying out pulse energy management through optimizing the average cavity dispersion and optical spectral bandwidth, 2.08 GHz repetition rate corresponding to 201 st harmonic with 36.5 dB side mode suppression ratio (SMSR) can be realized under 205 mW pump power at 1597.53 nm. Furthermore, we systematically investigate the characteristics of the harmonically mode locked ultrashort optical pulses with different spectral bandwidths versus pump power under fixed cavity dispersion first. Key laser parameters have been studied including pumping efficiency, duration, energy, SMSR, and time bandwidth product. Enlightened by the experimental results, a simple law on preliminary and fast judgment of pulses frequency under fixed pump power is proposed, namely, by monitoring the pulse spectral bandwidth. The laser source featuring high repetition rate and L-band operation is greatly sought-after in some specific applications such as modern optical communication system etc

Single/dual-wavelength switchable bidirectional Q-switched all-fiber laser using a bidirectional fiber polarizer

A single/dual-wavelength switchable bidirectional Q-switched fiber laser using a bidirectional fiber polarizer is demonstrated. A 45° tilted fiber grating is used as a bidirectional fiber polarizer to induce a bidirectional intracavity birefringence filter in both clockwise (CW) and counter-clockwise (CCW) directions. A carbon nanotube saturable absorber is employed to produce Q-switched pulses. Through adjusting polarization states, switchable single/dual-wavelength lasing at 1551 and 1560 nm can be achieved in both CW and CCW directions. To the best of our knowledge, this is the first demonstration of a wavelength switchable bidirectional passively Q-switched fiber laser

Mode locked Erbium doped fiber lasers using 45º tilted fiber grating

We have systematically studied the 45º tilted fiber grating (45TFG) as a functional device for Erbium doped fiber laser (EDFL) mode locking. A number of 45TFGs with different polarization dependent loss (PDL) have been fabricated. Mode locked Erbium doped fiber laser using these devices have been characterized in terms of threshold, pulse duration, signal to noise ratio (SNR), and spectral width. Our results show that a 45TFG with higher PDL could achieve better laser results. By using a 45TFG with 24dB PDL, the mode locked laser has 8.1% conversion efficiency and a threshold of 200mW

Observation of chaotic polarization attractors from a graphene mode locked soliton fiber laser

We have demonstrated an all-fiber passively mode locked erbium-doped fiber laser (EDFL) based on graphene–polyvinyl-alcohol film. By watchfully adjusting the polarization controller, two different polarization attractors, including polarization locked vector solitons and a circular attractor, can be observed. This is first time, to the best of our knowledge, to explore the dynamics polarization attractors exhibited by a vector soliton generated from an EDFL based on graphene

Dual pulse bound states in a dispersion-managed mode-locked all-fiber laser with 101.75MHz repetition rate using 45° tilted fiber grating

We demonstrate a dispersion managed Erbium doped all-fiber laser with 101.75MHz repetition rate using 45°TFG to realize mode locking based on nonlinear polarization rotation technique. In our experiment, stable dual-pulse tightly bound states were observed under the pump power of 505mW