A5081862366- Photonic Crystal and Fiber Optics
- Advanced Fiber Laser Technologies
- Advanced Fiber Optic Sensors
- Optical Network Technologies
- Solid State Laser Technologies
- Laser-Matter Interactions and Applications
- Laser Material Processing Techniques
- Semiconductor Lasers and Optical Devices
- GaN-based semiconductor devices and materials
- Advanced optical system design
- Photonic and Optical Devices
- Advanced Surface Polishing Techniques
- Semiconductor materials and devices
- Glass properties and applications
- Laser Design and Applications
- Advanced Machining and Optimization Techniques
- Inorganic Chemistry and Materials
Laser Zentrum Hannover
2012-2021
We report on an ytterbium-doped monolithic fiber laser at a wavelength of 1018 nm with output power 200 W in continuous wave operation. The optimal parameters for setting up such high-power are investigated and discussed detail. An in-house-developed pump light stripper single-mode fused coupler were applied to use the core-pumping amplifiers setup.
An all-glass microstructured high-power cladding mode stripper capable of handling light up to a power approximately 350 W with stripping efficiencies >22 dB is presented. optimized graded structure pattern increased the device's reliability and its power-handling capabilities. Subjected 500 h stress test, device shows no degradation.
We report on a variety of continuous wave and pulsed laser sources based Thulium- Holmium-doped materials, emitting in the spectral range around 2 μm. This includes Thulium-doped fiber lasers which have been realized beam combining technique by using tapered fused bundles truly single mode WDM cascades, respectively. A source nano- or picosecond pulses has developed master oscillator power amplifier (MOPA) configuration, consists gain-switched diode operating at wavelength 1.95 μm, followed...
In this paper we present a high power, polarized 2 μm Thulium-doped fiber laser with beam quality. Such systems are ideally suited for the processing of plastic materials which highly transparent in visible and 1 wavelength range pumping sources mid-IR region. For most applications lasers beneficial, as they can be easily protected from back reflections combined other or power scaled by polarization combining. The Tm-doped is pumped an all-fiber configuration using coupled pump diode...
We here discuss recent progress on astronomical optical frequency comb generation at innoFSPEC-Potsdam. Two different platforms (and approaches) are numerically and experimentally investigated targeting medium low resolution spectrographs facilities in which innoFSPEC is currently involved. In the first approach, a generated by propagating two lasers through three nonlinear stages – serve for of low-noise ultra-short pulses, while final stage low-dispersion highly-nonlinear fibre where...
The generation of a broadband optical frequency comb with 80 GHz spacing by propagation sinusoidal wave through three dispersion-optimized nonlinear stages is numerically investigated. input power, the dispersion, coefficient, and lengths are optimized for first two low-noise ultra-short pulses. final stage low-dispersion highly-nonlinear fibre where pulses undergo self-phase modulation strong spectral broadening. modeling performed using Generalized Nonlinear Schrodinger Equation...
We here report on recent progress astronomical optical frequency comb generation at innoFSPEC-Potsdam and present preliminary test results using the fiber-fed Multi Unit Spectroscopic Explorer (MUSE) spectrograph. The is generated by propagating two free-running lasers 1554.3 1558.9 nm through dispersionoptimized nonlinear fibers. centered 1590 comprises more than one hundred lines with an optical-signal-to-noise ratio larger 30 dB. A crystal used to double whole spectrum, which efficiently...
CO2 laser radiation is a versatile tool for the fabrication of cladding light strippers in very thin claddings, particular if combined with AR-coated end-caps as monolithic and low-cost alternative to SMA-like connectors.
We present a CO2-laser based machining process for the manufacturing of all-fiber components. A beam is used to perform multiple steps chain. The first step removal fiber's polymer coating, followed by large parts glass cladding access buried waveguides fiber. Excellent surface quality (Ra <10 nm) and control precision are demonstrated, thus enabling fiber low loss evanescent field coupler (0.13 dB) was manufactured coupling between two cores achieved fusing altered fibers together.
Ultra-large mode area thulium-doped photonic crystal fibers (Tm:PCF) have enabled the highest peak powers in 2 micron fiber laser systems to date. However, Tm:PCFs are limited by slope efficiencies of <50% when pumped with 790 nm diodes. A well-known alternative is pumping at 1550 erbium/ytterbium-doped (Er/Yb:fiber) lasers for approaching ~70%. these pump also relatively inefficient themselves. recently demonstrated and more attractive approach enable over 90% thuliumdoped step-index...
Efficiencies <50% are typical in large mode area, thulium-doped photonic crystal fibers when pumped at 790nm. These thermal loads limit power scaling. In this work, we investigate resonant pumping and demonstrate slope efficiencies >64%.
Signal beam combining of Tm-doped fiber lasers can increase the laser output power while simultaneously maintaining single mode quality. We demonstrate an all-fiber integrated dual-wavelength with 36 W by using spectral method. The constituent are operating at wavelengths 1949 and 1996 nm in-house-made WDM is used for combination these two different wavelengths. All-fiber truly demonstrated first time in this wavelength region.
To answer a growing demand in development of high power pulsed and continuous wave sources at 2 micron spectral range we have participated several projects, which resulted delivery versatile monolithic providing picosecond, nanosecond CW laser signal. As an example developed all-fiber devices based on directly modulated diode gain-switched to generate picosecond pulses, respectively, are amplified the same fiber amplifier chain up 50 µJ with 96 ps more than 1 mJ pulses longer 35 ns.
We report on novel fabrication schemes of versatile cladding light strippers and end-caps via CO<sub>2</sub> laser radiation. integrated in SMA-like connectors for reliable stable fiber-coupling high-power diodes. Moreover, the application typical fiber geometries lasers was evaluated. In addition, we also developed processes to fuse end faces radiation inscribe fibers with near end-cap. Corresponding results indicate great potential such devices as a monolithic low-cost alternative SMA connectors.
The evanescent field coupling between fibers plays an important role in many different applications such as novel sensors to detect variations of the environmental refractive index [1] or broad fiber-based band-pass filters [2]. We are particularly interested fused fiber couplers that allow for light into higher order modes via [3]. Such devices very attractive increasing number channels large-scale telecommunication networks by implementation spatial multiplexing. For fabrication couplers,...
We present a turn-key pulsed polarized Holmium doped fiber source at 2088 nm. In our experimental setup we are utilizing an acousto-optic modulator as mode-locker or Q-switch. The linear cavity is comprised of Bragg grating (FBG) pair with central wavelength nm in polarization maintaining passive fiber. active maintaining, Holmium, and pumped in-house made Thulium laser emission 1940 maximum output power more than 10 W. q-switch operation it was possible to generate stable nanosecond pulses...
We report gamma radiation influence on an active Er3+ doped fiber amplifier. Hydrogenation of fibers under special condition allowed for a hardness increase by order magnitude. Stability and longevity hydrogenation effects are investigated.
We report the first fully monolithic, polarized, fiber amplifier based on resonantly pumped Holmium doped optical fibers at wavelength longer than 2050 nm. With commercially available fibers, it was possible to achieve Watt level output powers 2088