Diode Lasers

Fiber-coupled diode lasers are among the least expensive and most efficient beam sources for cw laser applications; they are widely used, for example, in the hardening, soldering and welding of metals. Fraunhofer ILT develops diode lasers for tailor-made optical systems that meet high requirements. With its own self-developed as well as commercial software tools, the institute models and optimizes complex laser systems. Direct diode lasers with kW optical output power are a cost-effective alternative to fiber lasers in cutting applications. The stabilized emission spectrum and beam quality of the diode laser can also be used to great advantage in pump applications for multi-kW fiber lasers or ultra-short pulse lasers. In addition to targeted beam shaping, the institute also focuses its R&D activities on developing fiber coupling and wavelength stabilization of diode lasers.

The range of services it offers includes R&D in the field of design and simulation, experimental investigations of laboratory samples, the development of industry-oriented, certified prototypes and comprehensive technology consulting as well as market and feasibility studies.

Characterization of High Power Diode Lasers

• Near and far field patterns and spectral distribution
• Wall plug efficiency and output power
• Polarization
• Emitter-resolved analysis of diode laser bars
• “Smile" measurement and strain analysis

Spectral Design

• External resonators (Fiber Bragg Gratings, Volume Gratings) for frequency stabilization
• Dense wavelength multiplexing
• Analysis of thermal wavelength shift
• Design and manufacturing of Volume Gratings

High Power Diode Laser Systems

• Beam shaping of single emitters and laser bars
• Systems based on Broad Area Lasers, (DBR) Tapered Lasers, Ridge Lasers and Quantum Dot Lasers
• Spatial multiplexing of single emitters for multimode fiber coupling
• Beam transformation and multimode fiber coupling of laser bars
• Fiber coupling of single mode emitters
• Super-pulsed diode lasers
• Algorithms for automated assembly of micro optics

Witte, U., Schneider, F., Holly, C., Di Meo, A., Rubel, D., Boergmann, F., Traub, M., Hoffmann, D., Drovs, S., Brand, T., Unger, A.:
kW-class direct diode laser for sheet metal cutting based on commercial pump modules.
High-Power Diode Laser Technology XV, San Francisco, California, United States, 28. Januar – 2. Februar 2017. Proc. SPIE Vol. 10086 (13 S.) (2017)

Neumann, A., Giesberts, M., Witte, U., Fitzau, O., Hoffmann, H.-D.:
Analytical model for diode-to-fiber coupling and beam propagation in weakly guiding fibers.
2017 IEEE High Power Diode Lasers and Systems Conference (HPD), 11 Oct - 12 Oct 2017, Coventry, UK.
Proc. IEEE High Power Diode Lasers & Systems, 35-36 (2017)

Witte, U., Traub, M.:
Cost efficient diode laser beam source for sheet metal cutting
Laser Techn. J. 14 (1), 36-39 (2017)

Schimmel, G., Janicot, S., Hanna, M., Decker, J., Crump, P., Erbert, G., Witte, U., Traub, M., Georges, P., Lucas-Leclin, G.:
Coherent beam combining architectures for high power tapered laser arrays
Proc. SPIE 10086, 100860O (11 S.) (2017)

Witte, U., Schneider, F., Traub, M., Hoffmann, D., Drovs, S., Brand, T., Unger, A.:
kW-class direct diode laser for sheet metal cutting based on DWDM of pump modules by use of ultra-steep dielectric filters
Opt. Expr. 24 (20), 22917-22929 (2016)

Fraugeron, M., Klein, S., Vilera, M., Kochem, G., Perez-Serrano, A., Krakowski, M., Traub, M.:
Laser module based on monolithically integrated MOPAs at 1.5 μm for space-borne lidar applications
ICSO 2016. International Conference on Space Optics. Biarritz, France, 18 - 21 October 2016. Paper 156 (8 S.) (2016)

Hengesbach, S., Klein, S., Holly, C., Witte, U., Traub, M., Hoffmann, D.:
Simultaneous frequency stabilization and high-power dense wavelength division multiplexing (HP-DWDM) using an external cavity based on volume Bragg gratings (VBGs)
Proc. SPIE 9733, 15 S. (2016)

Schimmel, G., Doyen, I., Janicot, S., Hanna, M., Georges, P., Lucas-Leclin, G., Decker, J., Crump, P., Erbert, G.: Kaunga-Nyirenda, S., Moss, D., Bull, S., Larkins, E. C., Witte, U., Traub, M.: 
High-power operation of coherently coupled tapered laser diodes in an external cavity
Proc. SPIE 9733, 11 S. (2016)

Witte, U., Traub, M., Di Meo, A., Hamann, M., Rubel, D., Hengesbach, S., Hoffmann, D.:
Compact 35μm fiber coupled diode laser module based on dense wavelength division multiplexing of NBA mini-bars, Proc. SPIE 9733, 12 S. (2016)

Faugeron, M., Vilera, M., Krakowski, M., Robert, Y., Vinet, E., Primiani, P., Le Goec, J.-P., Parillaud, O., Pérez-Serrano, A., Tijero, J. M. G., Kochem, G., Traub, M., Esquivias, I., van Dijk, F.:
High power three-section integrated Master Oscillator Power Amplifier at 1.5 µm
IEEE Photon. Technol. Lett. 27 (13), 1449-1452 (2015)

Hengesbach, S., Poprawe, R., Hoffmann, D., Traub, M., Schwarz, T., Holly, C., Eibl., F., Weisheit, A., Vogt, S., Britten, S., Ungers, M., Thombansen, U., Engelmann, C., Mamuschkin, V., Lott, P.:
Brightness and average power as driver for advancements in diode lasers and their applications
Proc. SPIE 9348, 93480B (18 S.) (2015)

Klein, S., Hengesbach, S., Westphalen, T., Traub, M., Hoffmann, D.:
Suppression of cross coupling in an external resonator for a diode laser bar with 19 single emitters 
Optics Letters 40, 641-644 (2015)

Rubel, D., Witte, U., Hengesbach, S., Traub, M., Hoffmann, D.:
Characterisation of ultra-narrow band filters for diode laser systems based on dense wavelength division multiplexing
2015 IEEE High Power Diode Lasers and Systems Conference (HPD), 14-15 Oct. 2015, 15-16 (2015)

Witte, U., Hamann, M., Di Meo, A., Rubel, D., Traub, M., Hoffmann, D.:
High power diode laser with 23W ex 35 μm fibre
2015 IEEE High Power Diode Lasers and Systems Conference (HPD), 14-15 Oct. 2015,17-18 (2015)

Witte, U., Rubel, D., Traub, M., Hamann, M., Hengesbach, S., Hoffmann, D.:
Dense wavelength multiplexing and 35 µm-fiber coupling of wavelength chirped high power diode laser bars
Advanced Solid State Lasers Conference 2015. Berlin, Germany, October 4-9, 2015. Paper AF1A.6 (3 S.) (2015)

Esquivias, I., Consoli, A., Krakowski, M., Faugeron, M., Kochem, G., Traub, M., Barbero, J., Fiadino, P., Ai, X., Rarity, J., Quatrevalet, M., Ehret, G.:
High-brightness all semiconductor laser at 1.57 µm for space-borne lidar measurements of atmospheric carbon dioxide: device design and analysis of requirements
Proc. SPIE 9135, 913516 (8 S.) (2014)

Hengesbach, S., Hoffmann, D., Traub, M., Poprawe, R.:
Comparison of edge emitter and vertical emitter based diode lasers for materials processing
Proceedings 33rd Int. Congress on Applications of Lasers & Electro-Optics (ICALEO), October 19-23, 2014, San Diego, USA, Paper 304
(9 S.) (2014)

Hengesbach, S., Holly, C., Krauch, N., Witte, U., Westphalen, T., Traub, M., Hoffmann, D.:
High-Power Dense Wavelength Division Multiplexing (HP-DWDM) of frequency stabilized 9xx diode laser bars with a channel spacing of 1.5 nm
Proc. SPIE 8965, 89650C (9 S.) (2014)

Holly, C., Hengesbach, S., Traub, M., Hoffmann, D.:
Numerical analysis of external feedback concepts for spectral stabilization of high-power broad-area semiconductor lasers
Proc. SPIE 8965, 89650K (8 S.) (2014)

Moench, H., Andreadaki, A., Gronenborn, S., Kolb, J. S., Loosen, P., Miller, M., Schwarz, T., van der Lee, A., Weichmann, U.:
High power electrically pumped VECSEL and arrays
Vertical External Cavity Surface Emitting Lasers (VECSELs) IV
Editor(s): Jerome V. Moloney. Proc. SPIE Vol. 8966 (10 S.) (2014)

Crump, P., Knigge, S., Maaßdorf, A., Bugge, F., Hengesbach, S., Witte, U., Hoffmann, H. D., Köhler, B., Hubrich, R., Kissel, H., Biesenbach, J., Erbert, G., Tränkle, G.:
Low-loss, smile-insensitive external frequency-stabilization of high power diode lasers enabled by vertical designs with extremely low divergence angle and high efficiency
Proc. SPIE 8605, 0T1-13 (2013)

Hengesbach, S., Witte, U., Traub, M., Hoffmann, D.:
Design of a DFB/DBR diode laser module including spectral multiplexing based on VBGs
High Power Diode Lasers and Systems Conference (HPD)
West Midlands, United Kingdom, 16-17 Oct. 2013
Piscataway, N.J.: IEEE 2013, pp. 16-17

Unger, A., Brand, T., Bull, S., Larkins, E. C., Traub, M., Hengesbach, S., Uusimaa, P., Vilokkinen, V., Crump, P., Erbert, G., Luclas-Leclin, G., Georges, P., Rataj, T., Deichsel, E.:
The Bridle project: High brilliance diode lasers for industrial applications
High Power Diode Lasers and Systems Conference (HPD), 2013
West Midlands, United Kingdom,16-17 Oct. 2013
Piscataway, N.J.: IEEE 2013, pp. 28-29

Witte, U., Hengesbach, S., Traub, M., Strotkamp, M., Jungbluth, B., Hoffmann, D.:
High brightness diode laser module in the red spectral range for pumping applications
High Power Diode Lasers and Systems Conference (HPD), 2013
West Midlands, United Kingdom,16-17 Oct. 2013
Piscataway, N.J.: IEEE 2013, pp. 30-31

Crump, P., Hengesbach, S., Witte, U., Hoffmann, H.-D., Erbert, G., Tränkle, G.:
High-power diode lasers optimized for low-loss smile-insensitive external spectral stabilization
IEEE Photon. Technol. Lett. 24 (8), 703-705, (2012)

Gilfer, C., Pavelescu, E.-M., Reitmaier, J. P., Westphalen, T., Traub, M., Michel, N., Krakowski, M.:
15-W fiber-coupled quantum-dot pump module
IEEE Photon. Technol. Lett. 24 (12), 1030-1032, (2012)

Heinemann, S., Lewis, B., Regaard, B., Schmidt, T.:
Single emitter based diode lasers with high brightness, high power and narrow linewidth. 
Proc. SPIE 7918, 79180M, (6 S.) (2011)

Hengesbach, S., Krauch, N., Holly, C., Traub, M., Witte, U., Hoffmann, D.:
High-power dense wavelength division multiplexis of multimode diode laser radiation based on volume Bragg gratings 
Opt. Lett. 38, 3154-3157, (2013)

Holly, C., Hengesbach, S., Traub, M., Hoffmann, D.:
Simulation of spectral stabilization of high-power broad-area edge emitting semiconductor lasers 
Opt. Expr. 21, 15553-15567, (2013)

Löhring, J., Meissner, A., Hoffmann, D., Fix, A., Ehret, G., Alpers, M.:
Diode-pumped single-frequency-Nd:YGG-MOPA for water-vapor DIAL measurements: design, setup and performance. 
Appl. Phys. B 102, 917-935, (2011)

Schulz-Ruhtenberg, M., Babushkin, I. V., Loiko, N. A., Huang, K. F., Ackermann, T.
Polarization properties in the transition form below to above lasing threshold in broad-area vertical-cavity surface-emitting lasers
Phys. Rev. A 81, 23819, (11 S.) (2010)

Vijayakumar, D., Jensen, O.B., Ostendorf, R., Westphalen, T., Thestrup, B.
Spectral beam combining of a 980 nm tapered diode laser bar
Opt. Expr. 18, 893-898, (2010)

Wueppen, J., Pawlowski, E., Traub, M., Jungbluth, B., Hasler, K.-H., Sumpf, B., Erbert, G.
Compact module of a frequency-doubled, cw diode laser with an output power of more than 500mW at 531nm and a beam quality of less than 1.3 
Proc. SPIE 7582, 758204, (8 S.) (2010)

Traub, M., Giesberts, M., Geiger, J., Johnigk, C., Hoffmann, H.-D.:
High peak power fiber coupled super-pulsed diode lasers
Proc. SPIE 7198, 71980W (10 S.) (2009)

Kochem, G., Traub, M., Hengesbach, S., Hoffmann, D.:
High power fiber coupled modules based on tapered diode-lasers at 975 nm
Proc. SPIE 7198, 71980R, (10 S.) (2009)

Kochem, G., Traub, M., Hengesbach, S., Hoffmann, D.:
High power fiber coupled modules based on tapered diode-lasers at 975 nm
Proc. SPIE 7198, 71980R, (10 S.) (2009)

Kochem, G., Haverkamp, M., Boucke, K.:
Frequency stabilized high brightness tapered amplifier and laser modules.
Proc. SPIE 6997, 69971-69971 (2008)

Miesner, J., Frischkorn, F., Boenig, N., Rose, D., Vahrenkamp, T., Boucke, K.:
Full automated packaging of high power diode laser bars
58th Electronic Components & Technology Conf. 2008, Lake Beuna Vista/Fl., USA, May 27 - May 30, 2008
Piscataways/N.J: IEEE Pr., (6 S.) (2008)

Michel, N., Lecomte, M., Parillaud, O., Calligaro, M., Krakowski, M., Westphalen, T., Traub, M.:
High-wall plug efficiency broad area laser bar with strain-compensated quantum well
Proc. IEEE 21st International Semiconductor Laser Conference (ISLC) September 14-18, 2008
pp. 103-104, (2008)

Haverkamp, M., Kochem, G., Boucke, K.:
Single mode fiber coupled tapered laser module with frequency stabilized spectrum
Proc. SPIE 6876, 68761D, (2008)

Leers, M., Boucke, K., Götz, M., Meyer, A., Kelemen, M., Lehmann, N., Monti di Sopra, F.:
Thermal resistance in dependence of diode laser packages
Proc. SPIE 6876, (10 S.) (2008)

Wessling, C., Hengesbach, S., Geiger, J., Dolkemeyer, J., Traub, M., Hoffmann, D.:
50 W passively cooled, fiber coupled diode laser at 976 nm for pumping fiber lasers using 100 µm fiber bundles
Proc. SPIE 6876, (11 S.) (2008)

Our services cover a wide range of topics. Related topics to fiber lasers and further research and development focuses can be found under the following links.