Generation of pulse-width controllable dissipative solitons and bound solitons by using an all fiber saturable absorber.

A passively mode-locked fiber laser with controllable pulse width is demonstrated by use of an all-fiber saturable absorber based on a hybrid no-core fiber (NCF)-graded index multimode fiber (GIMF) structure incorporated into an Er-doped fiber ring cavity. Such a hybrid NCF-GIMF structure has a tunable intracavity filtering effect. As a result, the mode-locking operation is achieved with controllable pulse width and spectral bandwidth in the normal dispersion regime by only stretching the fiber device.

Stretched graded-index multimode optical fiber as a saturable absorber for erbium-doped fiber laser mode locking.

A novel mode-locking method based on the nonlinear multimode interference in the stretched graded-index multimode optical fiber (GIMF) is proposed in this Letter. The simple device geometry, where the light is coupled in and out of the stretched GIMF via single-mode fibers, is demonstrated to exhibit the temporal intensity discrimination required for mode locking. The nonlinear saturable absorber (SA) characteristics of the device are controllable by simply adjusting the strength of the stretching applied.

High-efficiency 1064 nm nonplanar ring oscillator Nd:YAG laser with diode pumping at 885 nm.

We experimentally demonstrate a monolithic single-frequency nonplanar ring oscillator (NPRO) laser pumped by diode lasers from a thermally excited ground level directly into a metastable level of Nd:YAG gain medium. Continuous-wave output power of 4.54 W is obtained at 1064 nm with 7.

Saturable absorber based on a single mode fiber - graded index fiber - single mode fiber structure with inner micro-cavity.

An Er-doped mode-locked fiber laser with a saturable absorber based on single mode - graded index multimode - single mode fiber (SMF-GIMF-SMF) with inner micro-cavity is demonstrated. The modulation depth of the saturable absorber was measured to be 1.9% when the SMF-GIMF-SMF structure is bent to a certain state.

Long-term stable coherent beam combination of independent femtosecond Yb-fiber lasers.

We demonstrate coherent beam combination between independent femtosecond Yb-fiber lasers by using the active phase locking of relative pulse timing and the carrier envelope phase based on a balanced optical cross-correlator and extracavity acoustic optical frequency shifter, respectively. The broadband quantum noise of femtosecond fiber lasers is suppressed via precise cavity dispersion control, instead of complicated high-bandwidth phase-locked loop design. Because of reduced quantum noise and a simplified phase-locked loop, stable phase locking that lasts for 1 hour has been obtained, as verified via both spectral interferometry and far-field beam interferometry.

500 MHz spaced Yb:fiber laser frequency comb without amplifiers.

An optical frequency comb based on Yb:ring fiber laser was demonstrated. This is the first time, to our knowledge, f(ceo) has been generated directly from the oscillator without further amplifications above 500 MHz repetition rate. The signal-to-noise ratio of the offset frequency was above 40 dB at 300 kHz resolution bandwidth, which supports easy stabilization.

High-finesse cavity external optical feedback DFB laser with hertz relative linewidth.

We report hertz level relative linewidth distributed feedback diode lasers with external optical feedback from a high finesse F-P cavity, and demonstrate the efficient phase noise suppression and laser linewidth reduction of the optical feedback technique. The laser phase noise is dramatically suppressed throughout the measurement frequency range. Especially at the Fourier frequency of 17 kHz, approximately the linewidth of the F-P reference cavity, the laser phase noise is significantly suppressed by more than 92 dB.

Characterization of the carrier envelope offset frequency from a 490 MHz Yb-fiber-ring laser.

We present the characterization of the carrier envelope offset frequency of 490 MHz femtosecond Yb-fiber ring laser. After amplification and compression, 1.7 W 90 fs pulses were produced for octave-span-spectrum generation from 600 nm to 1300 nm.

Quasi synchronous tuning for grating feedback lasers.

A general analytical form of the round trip phase shift in grating feedback diode lasers is proposed. Using the new form, it is obvious that the round trip phase shift can be independent of rotation angle in first order approximation when only one restriction condition is met. We call this the quasi synchronous tuning (QST) condition.

External cavity diode laser with kilohertz linewidth by a monolithic folded Fabry-Perot cavity optical feedback.

We present a extended-cavity diode laser (ECDL) with kilohertz linewidth by optical feedback from a monolithic folded Fabry-Perot cavity (MFC). In our experiments, an MFC replaces the retroreflecting mirror in the traditional ECDL configuration. Beat-note measurements between this MFC-ECDL and a narrow-linewidth reference laser are performed and demonstrate that the linewidth of this MFC-ECDL is about 6.