Actively modelocked ring laser using Er-doped silica-based planarwaveguide amplifier

Nearly transform-limited picosecond pulses are generated from an actively modelocked ring laser using an Er-doped silica-based planar waveguide amplifier as the gain medium for the first time. 5.2 ps pulse width is obtained at 6.3 GHz and stable modelocking without pulse drop-off is confirmed at 2.2 GHz by bit error rate measurement     

非腔长匹配APM激光器的实验研究

本文在一新的非腔长匹配APM激光器中,首次实现连续Nd:YAG激光器的锁模运转,获得了频率200MHz、功率0.5W、脉冲宽度88ps的锁模脉冲输出,并分析了腔长对锁模运转的影响。     

2 cm long monolithic multisection laser for active modelocking at 2.2 GHz

A 2 cm long three-contact multisection laser has been fabricated for modelocking at very low repetition rates. Active modelocking yields 8.0-12.3 ps pulses at 2.2, 4.3 and 6.5 GHz corresponding to the fundamental, first, and second harmonics of the cavity resonance frequency. This device demonstrates the feasibility of fabricating monolithic pulse sources operating at rates as low as the OC-48 Sonet transmission rate (2.488 Gbit/s).<>     

Extended-cavity surface-emitting diode laser as active mirror controlling modelocked Ti:sapphire laser

Directly controlled, stable modelocking of a Ti:sapphire oscillator is demonstrated using a commercially available electrically pumped vertical extended-cavity surface-emitting laser as an active saturable absorber mirror. Modelocking is controlled by applying a pulsed current to the saturable absorber. Pulse durations of /spl sim/330 ps are observed.     

Colliding-pulse modelocked quantum dot lasers

Colliding pulse modelocking is demonstrated for the first time in quantum dot lasers. Using 3.9 mm-long devices with a 245 /spl mu/m-long central absorber, 7 ps pulses at a repetition rate of 20 GHz is obtained. For Gaussian pulses a time-bandwidth product close to the Fourier transform limit is determined. These results confirm the potential of quantum dot lasers for high repetition rate harmonic modelocking.     

Active modelocking of miniature fibre Fabry-Perot laser in ringcavity

Active modelocking at 10 GHz of a 10 mm-long fibre Fabry-Perot laser in a ring cavity is demonstrated. Very stable pulse trains without supermode noise were obtained. The pulsewidth was ~10 ps, which could be shortened to 1.6 ps by insertion of highly-nonlinear fibre     

1.5 /spl mu/m GaInNAs semiconductor saturable absorber for passively modelocked solid-state lasers

Fully self-starting and passively modelocking of a 1.5 /spl mu/m solid-state laser with a GaInNAs semiconductor saturable absorber mirror (SESAM) has been demonstrated for the first time. A saturation fluence of 20 /spl mu/J/cm/sup 2/, a modulation depth of 0.39% and a fast temporal decay of 18 ps were measured. These well-suited nonlinear optical SESAM parameters allowed for self-starting and passive modelocking of a diode-pumped Er:Yb:glass laser at 1.534 /spl mu/m with a pulse duration of 5 ps at 61 MHz.     

Controlled amplifier modelocked Er/sup 3+/ fibre ring laser

An erbium-doped fibre ring has been actively modelocked with an InGaAsP semiconductor amplifier employed as a modulator. Pulses having durations <4ps and peak powers of approximately 2 W around 1536 nm have been generated at a repetition frequency of 612 MHz by this new technique of controlled-amplifier modelocking (CAM).<>     

拍频自反馈锁模光纤环形激光器

报道一种由光纤环形激光器的拍频信号中提取高重复率正弦电信号，并以此信号调制腔内强度调制器，实现调制频率与腔长自适应的主动锁模方法。采用此方法获得重复率为２．５ＧＨｚ，脉宽为１１ｐｓ的变换极限超短光脉冲。     

Antimonide semiconductor saturable absorber for 1.5 /spl mu/m

Self-starting continuous-wave passive modelocking of an Er:Yb:glass laser at 1535 nm is demonstrated with the first antimonide semiconductor saturable absorber mirror (SESAM). The Er:Yb:glass laser produces 20 ps pulses at 61 MHz. This laser was used to characterise the nonlinear optical parameters of the metal organic vapour phase epitaxy grown SESAM.     

表面态型半导体可饱和吸收镜实现Nd:YAG激光器被动锁模

砷化镓半导体材料与空气接触的表面存在密度很高的电子表面态，砷化镓材料内部的电子可以通过这种表面进行驰豫，驰豫时间估计在ps量级。依此原理，制作了一种新型的表面态型半导体可饱和吸收镜，用其作为被动锁模吸收体．实现了半导体端面泵浦Nd：YAG激光器被动连续锁模。在泵浦功率为4W的情况下．获得了连续锁模脉冲序列，重复频率150MHz，锁模脉冲平均输出功率为300mW，脉冲宽度为10ps。     

Modelocking of interferometric Y-lasers in an external cavity

The first report on active modelocking of interferometric Y-lasers in an external cavity are reported. Pulse widths between 20 and 30 ps for 1.3-μm and 1.55-μm devices were achieved by modulation of the injection current synchronously to the external cavity roundtrip frequency. A time-bandwidth-product of 0.97 was determined for 1.55-μm devices     

High spectral tuning range of a modelocked InGaAs/InGaAsP MQW laserdiode due to light hole gain contribution

We report on modelocking of an external cavity multi quantum well semiconductor laser with an extremely wide spectral tuning range. Pulse widths in the order of 30 ps were obtained spectrally tunable from 1448 to 1563 nm. The broadening of the gain spectrum is experimentally shown to be due to the additional contribution of the electron n=1 to the light hole n=1 transition. This conclusion is supported by numerical calculations     

Kerr lens modelocked solid state laser in the red (639 nm)

The authors report Kerr lens modelocking of the Pr³⁺:YLF laser, operating at 639 nm, initiated through the use of a solid state saturable absorber, generating pulsewidths of 8 ps at repetition rates around 100 MHz     

以多掺杂YAG为调Q元件的主被动锁模激光器

报道一种新型主被动锁模激光器,它的饱和吸收体是一种新型多掺杂YAG晶体。以C轴YLF为工作物质时,得到的输出序列脉冲的平均能量为5.64mJ,能量起伏小于±5％,所占几率为96.9％,脉冲半宽平均为1.45ns;以Nd:YAG为工作物质时,输出序列脉冲能量平均为6.79mJ,能量起伏小于±4％,所占几率为96％,脉冲半宽平均为270ps。     

20 GHz transform-limited optical pulse generation and bit-error-free operation using a tunable, actively modelocked Er-doped fibre ring laser

The authors report the generation of 20 GHz, 3.0-3.5 ps transform-limited optical pulses across the wavelength tunable range 1550-1557 nm using a wavelength tunable, polarisation-maintaining actively modelocked Er/sup 3+/-doped fibre ring laser. Stable bit-error-free modelocking operation is confirmed throughout the wavelength tuning range.<>     

154 GHz polarisation-maintaining dispersion-managed activelymodelocked fibre ring laser

Optical pulses with a repetition rate of 154 GHz are generated directly from a polarisation-maintaining dispersion-managed fibre ring laser using fourth-order FM modelocking. External chirp compensation of the laser output yields transform-limited Gaussian pulses with 1.1 ps duration corresponding to a duty cycle of <0.2     

Coherent photon seeding of actively modelocked laser diodes with optical fibre cavities

A modified fibre cavity for obtaining single longitudinal laser diode mode operation in active modelocking is proposed. It has been shown that if a fusion spliced plane is incorporated inside the singlemode fibre cavity, the reflection from it can provide the feedback necessary for coherent photon seeding. 39.2 ps pulses with a spectral width of 0.14 nm have been generated.<>     

C.W. modelocking of a GaInAsP diode laser

Active c.w. modelocking of a GaInAsP double-heterostructure laser diode operating in an external cavity is reported. 18 ps pulses (f.w.h.m.) are obtained at a repetition rate of 2.1 GHz and a lasing wavelength of 1210 nm. The pulses were measured by autocorrelation using s.h.g. in LiIO3. They are the shortest pulses ever reported for a c.w. laser diode.     

All-optical actively modelocked fibre ring laser based on cross-gain modulation in SOA

A novel actively modelocked fibre ring laser based on cross-gain modulation in a semiconductor optical amplifier (SOA) employed as both the gain medium and modelocking element has been demonstrated. Stable uniform pulse trains with pulse-widths about 21 ps at 5 GHz repetition frequency were obtained. The entire laser was operated in the optical domain with a large tuning range that could probably span the whole gain region of the gain medium employed.