Dual-Wavelength Erbium-Doped Fibre Ring Laser by Cascading Tunable Bandpass Filter with Bandstop Filter

A novel fibre ring laser is proposed and successfully demonstrated. By cascading a tunable bandpass filter with a bandstop filter to construct the desired narrow dual-transmission-peak spectrum, and employing a segment of unpumped erbium-doped fibre as a saturable absorber, a stable fibre ring laser is achieved at room temperature. The proposed laser can operate in dual-wavelength with the wavelength spacing of 0.48 nm and the extinction ratio more than 50 dB or switch between the two wavelengths by adjusting a polarization controller. The stability is investigated experimentally and explained theoretically.     

A Dual-Wavelength Cladding-Pumped Er^3＋/Yb^3＋ Codoped Fibre Laser System with More Than 2 W Output and Tunable Wavelength Spacing

A dual-wavelength laser system with wideband tunable wavelength spacing and more than 2 W output power is proposed and demonstrated. The operation principle of the laser system is based on the saturation gain characteristic of a cladding-pumped Era＋ /yba＋ co-doped fibre amplifier combining with a wideband tunable fibre laser with fiat power spectrum. The tuning range of the wavelength spacing is continuous within a 35 nm spectral range, and the power difference between both lasing wavelengths can be easily adjusted and controlled by a variable optical attenuator. The total output power can approximately keep unchangeable when the wavelength spacing and the power difference between both lasing wavelengths are continuously tuned and changed. The maximum total output power of the laser system is about 2.22 W.     

Low Timing Jitter and Tunable Dual-Wavelength Picosecond Pulse Generation from a Fabry--Pérot Laser Diode with External Injection

A novel scheme to generate tunable dual-wavelength optical pulses with low timing jitter at arbitrary repetition rates is proposed and demonstrated experimentally. The pulses are generated from a gain-switched Fabry-Pérot laser diode with two external cw beams for injection seeding simultaneously. The cw light is generated by two independent distributed feedback laser diodes, and their wavelengths can be tuned independently by two temperature controllers. The dual-wavelength pulses with the pulse width of 57 ps, the timing jitter of 340 fs, are obtained. The sidemode-suppression ratio of the output pulses is better than 23dB over a 10-nm wavelength tuning range.     

Synchronization of an Ultrafast Ti：Sapphire Laser to the S-Band Microwave

We have synchronized a 102-MHz ultrafast self-mode-locked Ti:sapphire laser to a 2856-MHz rf source with thesample-locking technology. The relative root-mean-square time-jitter is 0.57 ps and the maximum time jitter is2.60ps. This is the first time that synchronization between the ultrafast laser pulse and the s-band microwavehas been accomplished in China. Potential applications include synchronization of lasers and rf power sources inparticle accelerator experiments and high-resolution pump-probe experiments.     

An all-solid-state high power quasi-continuous-wave tunable dual-wavelength Ti：sapphire laser system using birefringence filter

This paper describes a tunable dual-wavelength Ti:sapphire laser system with quasi-continuous-wave and high-power outputs. In the design of the laser, it adopts a frequency-doubled Nd:YAG laser as the pumping source, and the birefringence filter as the tuning element. Tunable dual-wavelength outputs with one wavelength range from 700~nm to 756.5~nm, another from 830~nm to 900mn have been demonstrated. With a pump power of 23~W at 532~nm, a repetition rate of 7~kHz and a pulse width of 47.6~ns, an output power of 5.1~W at 744.8~nm and 860.9~nm with a pulse width of 13.2~ns and a line width of 3~nm has been obtained, it indicates an optical-to-optical conversion efficiency of 22.2{\%}.     

Long-Term Stabilization of Carrier-Envelope Phase for Few Cycles Ti：Sapphire Laser Amplifier

We realize a long-term carrier-envelope phase （CEP） stabilization for a chirped pulse amplified Ti：sapphire laser by locking the oscillator and amplifier independently. Based on the measurement of CEP by employing f-to-2f interference technique between the octave-spanning spectrum which is generated from a rare gas filled hollow fiber, continuous locking time up to 7.2 h with 85 mrad fluctuation is demonstrated. Finely compensating the dispersion by a set of chirped mirrors, quasi-mono cycle pulses as shorter as 3.8 fs are obtained. Further experimental research on high harmonic generation dependence on CEP shown the waveform of laser pulses has been successfully controlled.     

Compact Single-Stage Femtosecond Multipass Ti：Sapphire Amplifier at 1 kHz with High Beam Quality

A compact femtosecond Ti：sapphire amplifier system is reported using single-stage multipass configuration with high beam quality. A high dispersion glass stretcher and a pair of double prisms for compression are introduced based on broadband femtosecond seed pulses. The non-grating-based pulse stretcher and compressor are advantageous to increase high beam quality and to reduce the high-order dispersion. A Gaussian filter is used to reduce the gain narrowing effect in amplification. The compact femtosecond Ti：sapphire nine-pass amplifier delivers pulses with a duration of 26 fs and an energy of 800μJ at 7mJ pumping pulses energy at I kHz. The 1-kHz femtosecond amplifier with high beam quality and high stability is very suitable for ultrafast physics research applications, such as attosecond science, ultra-precision micromachining, and THz wave generation.     

A Narrow Bandwidth BBO Optical Parametric Oscillator Injection－seeded by a Tunable Pulsed Ti：Sapphire Laser

Ａ　Ｎａｒｒｏｗ　Ｂａｎｄｗｉｄｔｈ　ＢＢＯ　Ｏｐｔｉｃａｌ　Ｐａｒａｍｅｔｒｉｃ　Ｏｓｃｉｌｌａｔｏｒ　Ｉｎｊｅｃｔｉｏｎ－ｓｅｅｄｅｄ　ｂｙ　ａ　Ｔｕｎａｂｌｅ　Ｐｕｌｓｅｄ　Ｔｉ：Ｓａｐｐｈｉｒｅ　ＬａｓｅｒＡＮａｒｒｏｗＢａｎｄｗｉｄｔｈＢＢ...     

Experimental Study on Dual Wavelength and Dual Pulse Q-Switched Frequency Doubling on a Tunable Cr： LiSAF Laser

A flashlamp-pumped Cr：LiSAF laser system with a voltage controlled Q-switch structure in the cavity is designed. A dual-wavelength and dual-pulse tunable laser output is gained. The relation of laser output behavior with input energy is studied experimentally. The output is dual-pulsed with the energy of the 32m J/pulse producing the total output energy of 64mJ and the pulse width is about 27ns at 850nm. Then, we use one LBO crystal as the frequency doubling crystal to obtain a dual wavelength （448.1 nm and 449.15nm） and dual pulse laser. The output for one wavelength is about 10.3mJ and the line width is less than 0.02nm.     

Experimental Study on Laser Behaviours of Ti：Sapphire Crystal Grown by IFUS Method

ＥｘｐｅｒｉｍｅｎｔａｌＳｔｕｄｙｏｎＬａｓｅｒＢｅｈａｖｉｏｕｒｓｏｆＴｉ：ＳａｐｐｈｉｒｅＣｒｙｓｔａｌＧｒｏｗｎｂｙＩＦＵＳＭｅｔｈｏｄＥｘｐｅｒｉｍｅｎｔａｌＳｔｕｄｙｏｎＬａｓｅｒＢｅｈａｖｉｏｕｒｓｏｆＴｉ：ＳａｐｐｈｉｒｅＣｒｙｓｔａｌ...     

All-Solid-State Nd:YAG Laser Operating at 1064nm and 1319nm under 885nm Thermally Boosted Pumping

We report a high-effciency Nd：YAG laser operating at 1064 nm and 1319nm, respectively, thermally boosted pumped by an all-solid-state Q-switched Ti：sapphire laser at 885 nm. The maximum outputs of 825.4 m W and 459.4mW, at 1064nm and 1319nm respectively, are obtained in a 8-ram-thick 1.1 at.% Nd：YAG crystal with 2.1 W of incident pump power at 885nm, leading to a high slope efficiency with respect to the absorbed pump power of 68.5% and 42.0%. Comparative results obtained by the traditional pumping at 808nm are presented, showing that the slope efficiency and the threshold with respect to the absorbed pump power at 1064nm under the 885nm pumping are 12.2% higher and 7.3% lower than those of 808rim pumping. At 1319nm, the slope efficiency and the threshold with respect to the absorbed pump power under 885nm pumping are 9.9% higher and 3.5% lower than those of 808 nm pumping. The heat generation operating at 1064 nm and 1319 nm is reduced by 19.8% and 11.1%, respectively.     

Tunable Ti: Sapphire regenerative amplifier for femtosecond Chirped-Pulse Amplification

We describe a tunable Ti:Sapphire regenerative amplifier which is used to amplify 120 fs pulses from a self-mode-locked Ti:Sapphire laser to energies in the range of 7–12 mJ from 760 nm to 855 nm. We have used three sets of cavity mirrors in the regenerative amplifier to vary the output wavelength of the laser.On leave from Institute of Laser Engineering, Osaka University, 2-6, Yamada-oka, Osaka 565, Japan (Fax: +81-6/877-4799)     

Efficient generation of 200 mJ nanosecond pulses at 100 Hz repetition rate from a cryogenic cooled Yb:YAG MOPA system

A diode-pumped Master Oscillator Power Amplifier (MOPA) laser system based on cryogenic cooled Yb:YAG has been designed, developed and its output performance characterised. The laser system consists of a fibre oscillator, an active mirror regenerative amplifier and a four pass main amplifier. 2.4 mJ, 10 ns, 100 Hz seed pulses from the fibre oscillator/regenerative amplifier arrangement were amplified up to pulse energies of over 200 mJ by using the four pass main amplifier arrangement. As a further study we have obtained an increased slope efficiency of 40% and an optical-to-optical efficiency of 30% using a pinhole vacuum spatial filter/image relay for laser mode control. With 1.8 mJ input seed pulses, output pulse energies of around 150 mJ were achieved.     

A High-Energy Good-Beam-Quality Krypton-Lamp-Pumped Nd：YAG Solid-State Laser with One Pump Cavity

We investigate a high-energy good-beam-quality krypton-lamp-pumped pulsed Nd： YA G solid-state laser with one pump cavity. The symmetrical resonator laser is developed and is rated at 80 J with beam parameter product 12mm mrad. The total system electro-optics efficiency of the lamp-pumped YAG laser is as high as 3.3% and the stability of output energy is ±2% with pulse width tunable between 0.1 ms and 10ms. The experimental results are consistent with the theoretical analysis and simulation.     

Generation of 170-fs Laser Pulses at 1053nm by a Passively Mode-Locked Yb:YAG Laser

A novel method is developed to obtain 1.05μm laser operation with a Yb：YAG laser. By using a Yb：YAG crystal with proper length and doping concentration, a femtosecond Yb： YAG laser is realized at the central wavelength of 1053nm. The measured pulse duration and spectral bandwidth （FWHM） are 170fs and 7nm; the repetition rate is 80 MHz. Under a power pump of 2 W, an average mode-locking power of 180mW is achieved.     

Tunable sub-100 femtosecond dye-laser pulses generated with a nanosecond pulsed pumping

Subpicosecond pulses at a fixed wavelength produced with a low-Q cavity dye laser pumped by a single, nanosecond laser (Q-switched Nd:YAG) are converted into tunable high-power sub-100 femtosecond pulses by generation, spectral selection, amplification and compression of a supercontinuum. The tunable, chirped, high-energy pulses obtained are compressed with a prism pair. Energies up to 50 J in sub-100 fs pulses were obtained in the 540 to 650 nm range using 40 mJ of the Nd: YAG-laser pumping pulses at 532 nm. The whole sub-100 fs system including the low-Q dye laser uses only one Nd:YAG laser as a pump source.     

可调谐掺钛蓝宝石激光器的一种新型倍频器

介绍掺钛蓝宝石激光器的一种新的倍频系统,利用色散棱镜对把不同频率的激光从窨色散开,然后利用透镜使这些光从不同方向入射到ＢＢＯ晶体上,这些方向恰 好是这些光的ＢＢＯ晶体上的相位匹配角,从而不需倍频晶体在掺钛蓝宝石激光器的可调谐范围内均实现角度相位匹配。