Martin Maiwald
Ferdinand-Braun-Institut
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Publication
Featured researches published by Martin Maiwald.
Optics Letters | 2006
Martin Maiwald; Sven Schwertfeger; Reiner Güther; Bernd Sumpf; Katrin Paschke; Christian Dzionk; G. Erbert
600 mW second-harmonic blue light at 488 nm has been generated by use of a master-oscillator power amplifier diode laser system as a pump source with a maximum optical output power of 4 W in continuous-wave operation. For frequency doubling, a periodically poled MgO:LiNbO3 bulk crystal was used in a single-pass configuration. A conversion efficiency of 15% and an overall wall-plug efficiency of 4% were achieved.
Applied Optics | 2009
Martin Maiwald; Heinar Schmidt; Bernd Sumpf; G. Erbert; Heinz-Detlef Kronfeldt
We present a compact wavelength stabilized diode laser system at 671 nm on a micro-optical bench as a light source for shifted excitation Raman difference spectroscopy (SERDS). The laser system consists of two broad-area gain media in separate laser cavities using two reflection Bragg gratings with slightly different center wavelengths. A spectral width below 100 pm and a constant wavelength shift of 0.57 +/- 0.06 nm is obtained up to output powers of 250 mW. The suitability of this light source for SERDS is demonstrated using Raman spectra of ethanol with increasing concentrations of Cresyl Violet as the fluorescent contaminant.
Applied Spectroscopy | 2014
Martin Maiwald; Bernd Eppich; J. Fricke; A. Ginolas; F. Bugge; Bernd Sumpf; G. Erbert
A dual-wavelength Y-branch distributed Bragg reflector (DBR) diode laser at 785 nm is presented as an excitation light source for shifted excitation Raman difference spectroscopy (SERDS). The monolithic device was realized with deeply etched surface DBR gratings using one-step epitaxy. An optical output power of 140 mW was obtained in continuous-wave (CW) operation for each laser cavity, with emission wavelengths of the device at 784.50 and 785.12 nm. A spectral width of the laser emission of 30 pm (0.5 cm−1), including 95% of optical power, was measured. The mean spectral distance of both excitation lines is 0.63 nm (10.2 cm−1) over the whole operating range. Raman experiments using polystyrene as the test sample and ambient light as the interference source were carried out and demonstrate the suitability of the dual-wavelength diode laser for SERDS.
Proceedings of SPIE, the International Society for Optical Engineering | 2006
Katrin Paschke; J. Behrendt; Martin Maiwald; J. Fricke; H. Wenzel; G. Erbert
We report on distributed Bragg reflector tapered lasers having 6th order surface gratings and ridge waveguides simultaneously fabricated by wafer stepper lithography and reactive ion etching. Single longitudinal mode emission at 978 nm and a beam propagation ratio of M2 = 1.1 at 4.4 W have been obtained in quasi-continuous wave operation. In CW operation, a maximal output power of 2.5 W with a side-mode suppression ratio of more than 20 dB and a beam propagation ratio of M2 < 1.4 for the central lobe has been achieved.
Optics Letters | 2009
Martin Maiwald; Daniel Jedrzejczyk; Alexander Sahm; Katrin Paschke; Reiner Güther; Bernd Sumpf; G. Erbert
A microsystem excitation light source emitting at 488 nm is presented. A direct single-pass nonlinear frequency conversion using a diode laser emission at 976 nm and a periodically poled lithium niobate waveguide crystal for efficient second-harmonic generation is demonstrated. This was realized on a micro-optical bench with a combined thermal management and a footprint of (25 mm x 5 mm). At 217 mW fundamental power a generated power of 56 mW at 488 nm with a conversion efficiency of 26% was achieved. With a power stability below 1%, this wavelength stabilized compact device is well suited for Raman spectroscopy.
Applied Spectroscopy | 2009
Martin Maiwald; Heinar Schmidt; Bernd Sumpf; Reiner Güther; G. Erbert; Heinz-Detlef Kronfeldt
A microsystem light source emitting at 488 nm was tested and applied as a light source for shifted excitation resonance Raman difference spectroscopy (SERRDS). A nonlinear frequency conversion using a distributed feedback (DFB) diode laser emission at 976 nm and a periodically poled lithium niobate (PPLN) waveguide crystal was realized on a micro-optical bench with a footprint of 25 mm × 5 mm. Joint temperature management via the microbench is used for wavelength tuning. Two emission lines at 487.61 nm and 487.91 nm are used for the SERRDS experiments. The Raman spectra of the test sample polystyrene demonstrate that a laser bandpass filter did not need to be implemented. Resonance Raman spectra of Tartrazine (FD&C Yellow 5, E 102) in distilled water are presented to demonstrate the suitability of this light source for SERRDS in, e.g., food safety control.
Optics Letters | 2014
Norman Ruhnke; André Müller; Bernd Eppich; Martin Maiwald; Bernd Sumpf; G. Erbert
A high-power external cavity diode laser (ECDL) system with narrowband emission is presented. The system is based on a commercially available high-power GaN laser diode. For the ECDL, a maximum optical output power of 400 mW in continuous-wave operation with narrowband emission is achieved. Longitudinal mode selection is realized by using a surface diffraction grating in Littrow configuration. A spectral width of 20 pm at 445 nm with a side-mode suppression ratio larger than 40 dB is achieved. This concept enables diode laser systems suitable for subsequent nonlinear frequency conversion into the UV spectral range.
Optics Letters | 2008
Tran Quoc Tien; Martin Maiwald; Bernd Sumpf; G. Erbert
Wavelength-stabilized compact laser systems at 670 nm on a micro-optical bench are presented. The resonator concept consists of a tapered semiconductor gain medium and a reflection Bragg grating as a wavelength selective resonator mirror. In pulse operation mode with 100 ns pulses, an optical peak power of 5 W with a spectral width below 150 pm was achieved. Nearly diffraction-limited beam quality at optical output powers up to 1 W is obtained. Such laser systems can be used, e.g., for Raman spectroscopy and as pumping sources for frequency conversion toward UV spectral range.
IEEE Photonics Technology Letters | 2008
Martin Maiwald; A. Ginolas; André Müller; Alexander Sahm; Bernd Sumpf; G. Erbert
A wavelength-stabilized compact diode laser system emitting at 671 nm mounted on a microoptical bench with the dimensions of 13 mmtimes4 mm is presented. A reflecting Bragg grating was aligned on the rear side of a broad-area gain medium for wavelength stabilization at 671 nm. A maximum output power of 1.5 W was obtained together with a spectral width of 40 pm (full-width at half-maximum). At 1.0 W, a center wavelength stability below 20 pm over 5 h was determined. With these features, the devices are well-suited for spectroscopic applications.
IEEE Photonics Technology Letters | 2008
Bernd Sumpf; M. Zorn; Martin Maiwald; R. Staske; J. Fricke; P. Ressel; G. Erbert; Markus Weyers
Highly efficient 670-nm high-power broad-area laser diodes with a single InGaP quantum-well embedded in AlGaInP waveguide layers and n-AlInP and p-AlGaAs cladding layers are presented. The developed vertical layer structure leads to a vertical far-field angle of 31deg. At 15degC, 100 mu-m-wide broad-area lasers reach an output power of 5.6 W limited by thermal rollover. The conversion efficiency was 41% at 1.5 W. A 7600-h reliable operation at 1.5 W and a mean time to failure of about 37550 h will be reported.