高信噪比多波长2 μm主动锁模光纤激光器

介绍一种多波长掺铥主动锁模光纤激光器,增益介质为长2 m的掺铥光纤,主动锁模通过铌酸锂强度调制器实现。腔内加入基于双折射的光学滤波器,利用保偏光纤双折射滤波效应在滤除腔内多余超模噪声的同时,还可以实现多波长输出。基频下的锁模脉冲频谱信噪比可达68.48 dB,在稳定的锁模状态下波长信道数最大为5。此外,腔内偏振无关隔离器被替换为偏振相关隔离器后,将锁模脉冲加载数字信号同步调制,测得的眼图光信噪比提高了8.67 dB。测试结果表明,锁模脉冲的时间稳定性得到有效提升。     

Harmonic Mode-Locked Er-Doped Fiber Laser Based on a Microfiber-Based PbS Nanoparticle Saturable Absorber

Lead sulfide (PbS) is a nanomaterial with excellent optical and chemical properties, such as a narrow bandgap (0.37 eV), high thermal damage threshold, and high stability. Obviously, it is appropriate as a saturable absorber (SA) device for ultrafast photonics. However, PbS nanoparticles (NPs) as the SA of ultrashort harmonic mode-locked pulse still haven't been demonstrated at present. In this paper, the PbS NPs are made into an SA-device-based microfiber by optical deposition method and connected in an integrated Erbium-doped fiber laser. And both characteristics and nonlinear optical properties of PbS NPs have been systemically investigated. A fundamental frequency mode-locked pulsed laser is proposed, whose central wavelength is 1560 nm, and the pulse width is 1 ps. In addition, high repetition rate operations are achieved, with a maximum repetition rate of 833 MHz. This is the first time that PbS NPs are used to generate 96th-order harmonic mode-locking, and the corresponding pulse duration is 987 fs. It is demonstrated that PbS NPs are a kind of SA photonic material with excellent performance. It can improve the communication capacity by applying fiber communication, and it has potential application value even in material processing and optical comb.     

Yb:CaF2–YF3 transparent ceramics ultrafast laser at dual gain lines

Yb³⁺:CaF₂-YF₃ transparent ceramics with excellent optical quality was successfully fabricated by hot-pressed method. Pulsed laser properties of this ceramics were investigated for the first time. Laser diode (LD) was applied as the pump source to generate a dual-wavelength mode-locked (ML) laser. The maximum average output power was 310 mW, which represents the highest output power of ultrafast calcium fluoride ceramic laser. The spectrum separated at 1048.9 nm and 1049.7 nm with a total pulse duration of 8.9 ps. The interval period between the beating signals was about 4.3 ps, corresponding to a 0.23 THz beat pulse repetition rate. These results demonstrate its potential in producing dual-wavelength ultrashort pulses. These Yb³⁺:CaF₂-YF₃ ceramics with low-cost and short-preparation period are ideal candidate materials for ultrafast lasers.     

自启动被动锁模掺铒光纤激光器的研究

在非线性光纤环形镜非线性开关效应和块状半导体波导饱和吸收效应的共同作用下，实现了掺铒光纤激光器的自启动被动锁模，获得了十分稳定的锁模脉冲序列，观察到高次谐频锁模脉冲输出。分析了非线性光纤环形镜的非线性开关反射特性。     

Properties of LBO and Generation of Mode-locking Blue Femtosecond Pulses

ＰｒｏｐｅｒｔｉｅｓｏｆＬＢＯａｎｄＧｅｎｅｒａｔｉｏｎｏｆＭｏｄｅ┐ｌｏｃｋｉｎｇＢｌｕｅＦｅｍｔｏｓｅｃｏｎｄＰｕｌｓｅｓＨＵＡＮＧＦｅｉｒａｎＷＥＩＺｈｉｙｉＹＡＮＧＪｉｅＺＨＯＵＪｉａｎｙｉｎＹＵＺｈｅｎｘｉｎ（ＳｔａｔｅＫｅｙＬａｂｏｒａ...     

法布里－珀罗干涉仪外腔半导体激光器的选模和锁模特性研究

报道了法布里－珀罗干涉仪用作半导体激光器外腔的选模原理和选模及锁模实验。通过压电陶瓷调节Ｆ－Ｐ干涉仪的间距，实现了半导体激光器本身的静态及动态单纵模运转，在调制频率为６５６ＭＨｚ的情况下，获得了近变换极限的外腔锁模高斯形超短脉冲，脉宽为１３ｐｓ，时间带宽乘积为０．４６。最后讨论了Ｆ－Ｐ干涉仪对半导体激光器的模式特性的影响。     

The Experiment Study of Two Nd~（3＋）：p－glass Rods Laser with a Q－switch／mode－locking and Amplifier

ＴｈｅＥｘｐｅｒｉｍｅｎｔＳｔｕｄｙｏｆＴｗｏＮｄ￣（３＋）：ｐ－ｇｌａｓｓＲｏｄｓＬａｓｅｒｗｉｔｈａＱ－ｓｗｉｔｃｈ／ｍｏｄｅ－ｌｏｃｋｉｎｇａｎｄＡｍｐｌｉｆｉｅｒ￥ＲＥＮＺｈａｏｙｕ；ＺＨＵＡＮＧＤｏｕｎａｎ；ＬＥＩＳｈｉｚｈａｎ；ＹＵＧｕｉ...     

Studies on Passive Mode－Locking Characteristics of Nd：YAG Laser With a Nonlinear Coupled－Cavity

ＳｔｕｄｉｅｓｏｎＰａｓｓｉｖｅＭｏｄｅ－ＬｏｃｋｉｎｇＣｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆＮｄ：ＹＡＧＬａｓｅｒＷｉｔｈａＮｏｎｌｉｎｅａｒＣｏｕｐｌｅｄ－ＣａｖｉｔｙＳｔｕｄｉｅｓｏｎＰａｓｓｉｖｅＭｏｄｅ－ＬｏｃｋｉｎｇＣｈａｒａｃｔｅｒｉｓｔｉ...     

Design optimization of all-optical actively mode-locked ring laser based on cross-gain modulation in a semiconductor optical amplifier

A complete and detailed model is presented that describes the main physical phenomena that occur in an actively mode-locked fiber ring laser based on cross-gain modulation in a semiconductor optical amplifier employed as both the gain medium and mode-locking element. The relationship between key laser parameters and the output pulse characteristics is numerically analyzed to provide simple design rules and derive a set of necessary operational conditions. The adoption of these rules and the satisfaction of these conditions enables the optimization of the laser performance and the generation of short and high energy mode-locked output pulses.     

Cr^4＋：YAG在对撞脉冲锁模的Nd：YAG激光器中实现被动锁模的研究

在理论上提出了Ｃｒ＾４＋：ＹＡＧ作为可饱和吸收体在Ｎｄ：ＹＡＧ激光器中实现被动锁模的可能性，运用速率方程组导出在强激光脉冲作用下Ｃｒ＾４＋：ＹＡＧ激发态吸收的恢复时间和饱和光强。实验上在带有抗共振环结构的接近于介稳腔的脉冲式Ｎｄ：ＹＡＧ激光器中用Ｃｒ＾４＋：ＹＡＧ作为可饱和吸收体实现被动锁模运转，得到能量１３．５ｍＪ、平均脉宽１８０ｐｓ的锁模脉冲序列。