Ultrashort Pulse Distributed Feedback Tunable Solid State Lasers

Tunable ultrashort pulse laser sources are practically important for a wide range of applications, such as time-resolved spectroscopy, optical measurements, optical sensing, deployments in optical networks, etc. Generally, these laser sources can be achieved through a technique known as mode-locking. Many commercial laser products have been developed to meet the foregoing applications. Such kind of lasers with mode-locking techniques, no matter active or passive, even with cavity dumping, need complex and critical experimental setup. Distributed feedback (DFB) laser is a "mirrorless" laser source of narrowband output, and another important property is that it can generation tunable ultrashot pulse duration in some special cases. It is simple solution for generation of tunable ultrashort pulse compare with the lasers with mode-locking technique. Lots of works have been done on DFB lasers for this purpose.In this paper, we firstly give an introduction of development of DFB lasers and ultrashort lasers, and then demonstrate the basic theory of DFB lasers and the mechanism of ultrashort pulse formation of gain coupled ones. Based on the above theory we carry out our sesearch works in the following three steps. In the first step, we provide an innovative design of a DFB dye laser(DFDL) using solid state P567 as active medium. And then, we study the characteristics of this DFDL by computer simulation. In the second step, more like what we have done in the first step, we proceed a research of DFB Ti:sapphire laser(DFTL). In the last step, using the P567 solid dye samples made by a stepwise synthesis technique through a sol-gel process, some experiments were done on P567 DFDL.As results, we have made an innovative design for solid state dye DFB laser and Ti:saphhire DFB laser which introduce a prism in the pumping frame of above lasers, therefore ,these lasers can work in the first-order Bragg effect with lower threshold condition and higher conversion rates than in the high-order Bragg effect. The computer simulation indicate that generation of single picosecond pulses can beachieved from the P567 solid state dye DFB lasers with pulse energy of 2.43 μJ andTi:saphhire DFB laser with pulse energy of 2.64mJ. In the experimental study, we have established a P567 solid state dye DFB laser according to the second-order Bragg effect. Though we have not obtain the ideal results, we give a detail analysis to be used for reference of further studying.