Power stabilization of diode pumped solid state lasers by means of adaptive control of drive current

2019
Şentürk, Tayfun
Lasers provide precision and sensitivity for various applications. However, some fundamental properties make lasers very susceptible to external changes. When stability of laser parameters is required the traditional approach is to stabilize the working environment, such as strict temperature and climate control, mechanical isolation as well as damping of any vibration. This traditional approach is very difficult to implement in harsh industrial environments and almost impossible for many military applications. One frequently used state-of-the-art laser type in industrial and military applications is diode pumped solid state lasers. Fundamentally, temperature of various components, small deviations in optical properties and opto-mechanical alignments over time as well as aging cause output power of such lasers to drift away from the desired level. Tracking of all these critical stimuli is impractical and even when achieved, it would result in a complex multi-input control algorithm design. To overcome this difficulty, firstly, a reliable internal laser output energy measurement system is designed, implemented and tested under various operating conditions. The output from this sensor provides the feedback signal for the control algorithm. A closed-loop control system is expected to be designed and optimized for regulation of output energy of a SISO type laser device by setting the drive current adaptive to the environmental conditions. The algorithm and implemented system is experimentally tested.

Suggestions

Pumping chamber design in diode pumped solid-state lasers for maximum system efficiency and minimum optical distortion
Zengin, Kubilay; Sayan, Gönül; Yelen, Kuthan; Department of Electrical and Electronics Engineering (2013)
The beam quality and the system efficiency of a diode-pumped solid-state laser source are directly related to the thermal profile inside the laser crystal. The thermal profile in a laser crystal should be made uniform in order to reduce the negative effects of the thermal lens. However, the absorbed pump profile that forms a uniform thermal profile inside the gain medium may adversely affect the system efficiency. In this thesis, a computational and empirical method was developed for designing pumping chamb...
Simulation of thermal, mechanical and optical behavior of yag ceramics with increasing Nd3+ concentration under lasing conditions.
Kenar, Necmettin; Öke, Gülay; Department of Physics (2007)
Two-dimensional thermal, mechanical and optical simulations are carried out to investigate the effect of Nd3+ concentration on thermal, mechanical and optical behavior of Nd:YAG ceramic laser materials under continuous wave laser operation. In the analyses, rods are pumped longitudinally with laser diodes, in three, six, nine and twelve fold structures. Rods having diameters of 3 and 6 mm are pumped with 808 nm and 885 nm sources separately having Nd+3 concentrations of 0.6, 1, 2, 3, 4 and 6 at. %. Total ab...
Nano patterning of AISI 316L stainless steel with Nonlinear Laser Lithography: Sliding under dry and oil-lubricated conditions
Gnilitskyi, Iaroslav; Rotundo, Fabio; Martini, Carla; Pavlov, Ihor; Ilday, Serim; Vovk, Evgeny; Ilday, Fatih Omer; Orazi, Leonardo (2016-07-01)
Femtosecond laser-based Nonlinear Laser Lithography (NLL) was applied to AISI 316L stainless steel, which requires surface modification to achieve satisfactory tribological behaviour. NLL advances over the well-known Laser Induced Periodic Surface Structures (LIPSS) in terms of uniformity and long-range order of high speeds, over large areas. A galvanometric scanner head was used for an high production rate. Dry and lubricated sliding tests, considering different orientations of the nanotexture showed that ...
3D-graphene-laser patterned p-type silicon Schottky diode
Orhan, Elif Oz; Efil, Esra; Bayram, Ozkan; Kaymak, Nuriye; Berberoğlu, Halil; Candemir, Ozun; Pavlov, Ihor; Ocak, Sema Bilge (Elsevier BV, 2021-01-01)
© 2020 Elsevier LtdThe influence of the laser patterning (LP) process on the quality of graphene (Gr) film and Schottky diode characteristics was researched in this study. First of all, p-type silicon (Si) was patterned by homemade femtosecond laser source. To compare the resulting effect, non-patterned n-Si and p-Si were used as substrates. To achieve vertically oriented three-dimensional (3D) Gr nanosheets (VGNs) onto the laser patterned p-type Si, non-patterned n-Si, and p-Si substrates, we used Radio-Fr...
Development of a picosecond pulsed mode-locked fiber laser
Yağcı, Mahmut Emre; Altan, Hakan; Department of Physics (2013)
Fiber lasers represent the state-of-the-art in laser technology and hold great promise for a wide range of applications because they have a minimum of exposed optical interfaces, very high efficiency, and are capable of exceptional beam quality. In the near future, the most important markets such as micromachining, automotive, biomedical and military applications will begin to use this technology. The scope of this thesis is to design and develop a short picosecond pulsed fiber laser using rare-earth doped ...
Citation Formats
T. Şentürk, “Power stabilization of diode pumped solid state lasers by means of adaptive control of drive current,” Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Electrical and Electronics Engineering., Middle East Technical University, 2019.