ABSTRACT
We present a laser module with dimensions of 76×43×15m m 3 that for the first time to our knowledge realizes a coherent beam combination in such a compact device, using two tapered amplifiers seeded by a distributed Bragg reflector ridge waveguide laser diode operating at 761 nm in a single longitudinal mode. The generated combined optical power is up to 5 W continuous wave with a combing efficiency of 85%. The phase of the system is controlled by the current in the ridge waveguide section of one of the tapered amplifiers. The phase-stabilization process is automated using a reverse hill-climbing algorithm and an ATmega328P microcontroller.
ABSTRACT
Lasers with emission wavelengths in the near-ultraviolet (UV) spectral range have been used in many applications across various fields, and the demand for these lasers has been on the rise. For example, in medicine, near-UV light has been used for fluorophore excitation. Although laser diodes emitting in this region exist, single longitudinal mode lasers emitting at 380 nm with high optical power are limited. One of the solutions to this problem is the use of second harmonic generation by a non-linear crystal. In this work, single-longitudinal-mode laser emission at 380.5 nm with an optical power of up to 13 mW has been achieved. The emission was realized by frequency doubling using a periodically poled circular waveguide crystal of stoichiometric L i T a O 3 doped with MgO (PPMgSLT) pumped by a master oscillator power amplifier with optical power up to 5 W. A distributed Bragg reflector ridge waveguide laser diode at 761 nm was used as the master oscillator and a tapered amplifier as the power amplifier.
ABSTRACT
In this work, the influence of strong optical feedback on the emission behavior of distributed Bragg-reflector ridge waveguide diode lasers emitting at 1120 nm with different cavity lengths and facet reflectivities is investigated. Based on measurements of the optical output power, central emission wavelength, and spectral emission width, the different diode laser types are compared while optical feedback up to -8dB is applied. The observed changes of the optical output power and emission wavelength as well as the occurrence of coherence collapse states give insight into the resistance against feedback of the different diode laser types.
ABSTRACT
A red-emitting tapered diode laser with a monolithically integrated distributed Bragg reflector grating is presented. The device is able to emit up to 1 W of spectrally stabilized optical output power at 5°C. Depending on the period of the tenth order surface grating the emission wavelengths of these devices from the same gain material are 635 nm, 637 nm, and 639 nm. The emission is as narrow as 9 pm (FWHM) at 637.6 nm. The lateral beam quality is M(2)(1/e(2)) = 1.2. Therefore, these devices simplify techniques such as wavelength multiplexing and fiber coupling dedicating them as light sources for µ-Raman spectroscopy, absolute distance interferometry, and holographic imaging.
Subject(s)
Lasers, Semiconductor , Refractometry/instrumentation , Color , Equipment Design , Equipment Failure Analysis , Systems IntegrationABSTRACT
We report on a diode-pumped Yb:KGW (ytterbium-doped potassium gadolinium tungstate) laser with a repetition rate of 4.8 GHz and a pulse duration of 396 fs. Stable fundamental modelocking is achieved with a semiconductor saturable absorber mirror (SESAM). The average output power of this compact diode-pumped solid state laser is 1.9 W which corresponds to a peak power of 0.9 kW and the optical-to-optical efficiency is 36%. To the best of our knowledge, this is the femtosecond DPSSL with the highest repetition rate ever reported so far.
ABSTRACT
We measure the temperature distribution of a 3 cm long periodically poled LiNbO3 crystal in a single-pass second harmonic generation (SHG) setup at 488 nm. By means of three resistance heaters and directly mounted Pt100 sensors the crystal is subdivided in three sections. 9.4 W infrared pump light and 1.3 W of SHG light cause a de-homogenized temperature distribution of 0.2 K between the middle and back section. A sectional offset heating is used to homogenize the temperature in those two sections and thus increasing the conversion efficiency. A 15% higher SHG output power matching the prediction of our theoretical model is achieved.
ABSTRACT
We report on efficient single-pass, high-power second-harmonic generation in a periodically poled MgO-doped LiNbO3 planar waveguide using a distributed Bragg reflector tapered diode laser as a pump source. A coupling efficiency into the planar waveguide of 73% was realized, and 1.07 W of visible laser light at 532 nm was generated. Corresponding optical and electro-optical conversion efficiencies of 26% and 8.4%, respectively, were achieved. Good agreement between the experimental data and the theoretical predictions was observed.
Subject(s)
Lasers , Magnesium Oxide/chemistry , Niobium/chemistry , Oxides/chemistry , Spectrum AnalysisABSTRACT
We demonstrate a passively mode-locked femtosecond laser based on the self-frequency-doubling crystal Yb:Ca4YO(BO3)3. The oscillator is pumped by a novel two-section distributed Bragg-reflector tapered diode-laser. Pulses as short as 46 fs and 42 fs at 1050 nm are achieved for the E//Z polarization without and with external compression, respectively. These are, to the best of our knowledge, the shortest pulses obtained from an oscillator based on Yb3+-doped bulk material.
ABSTRACT
We present a diode-pumped Yb:KGW laser with a repetition rate of 1 GHz and a pulse duration of 281 fs at a wavelength of 1041 nm. A high brightness distributed Bragg reflector tapered diode laser is used as a pump source. Stable soliton modelocking is achieved with a semiconductor saturable absorber mirror (SESAM). The obtained average output power is 1.1 W and corresponds to a peak power of 3.9 kW and a pulse energy of 1.1 nJ. With harmonic modelocking we could increase the pulse repetition rate up to 4 GHz with an average power of 900 mW and a pulse duration of 290 fs. This Yb:KGW laser has a high potential for stable frequency comb generation.
Subject(s)
Lasers, Semiconductor , Models, Theoretical , Semiconductors , Signal Processing, Computer-Assisted/instrumentation , Computer Simulation , Equipment Design , Hot TemperatureABSTRACT
We study second-harmonic generation of picosecond pulses in bulk periodically poled lithium niobate using an all-semiconductor master oscillator-power amplifier with gain-switched seed as our fundamental source. Both during amplification and during the subsequent second-harmonic generation, the signal pulse shape improves, and the resulting pulses at 531 nm are nearly independent of the seed pump conditions. Over a wide range of repetition rates and seed settings, we obtain green pulses with a duration of less than 31 ps FWHM and a peak power of more than 5.1 W. We further investigate the influence of the fundamental's spectral dynamics on pulsed second-harmonic generation efficiency and obtain excellent agreement between our measurements and previously published theoretical treatments.
ABSTRACT
The mode locking of the mixed sesquioxide single crystal Yb:LuScO(3) is demonstrated. This crystal is locally disordered and has the broadest emission spectrum of all sesquioxides known so far. Pulse durations as short as 111 and 74 fs were obtained using the semiconductor saturable absorber mirror and Kerr-lens mode locking, respectively. The latter regime was reached using a two-section distributed Bragg-reflector tapered diode laser as a pump source.
ABSTRACT
A new approach for efficient second-harmonic generation using diode lasers is presented. The experimental setup is based on a tapered amplifier operated in a ring resonator that is coupled to a miniaturized enhancement ring resonator containing a periodically poled lithium niobate crystal. Frequency locking of the diode laser emission to the resonance frequency of the enhancement cavity is realized purely optically, resulting in stable, single-frequency operation. Blue light at 488 nm with an output power of 310 mW is generated with an optical-to-optical conversion efficiency of 18%.
ABSTRACT
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.
ABSTRACT
We demonstrate continues-wave 1 W at 490 nm on a 2.5 cm(3) micro-optical bench using single-path second-harmonic generation with a periodically poled MgO:LiNbO(3) bulk crystal. The pump laser is a distributed Bragg reflector tapered diode laser having a single-frequency spectrum and a pump power of 9.5 W. Based on that 1 W blue light could be achieved resulting in an optical conversion efficiency of 11%. Furthermore, the module has an output power stability of better than 2% and the blue laser beam shows an nearly diffraction limited beam quality of M(2)(sigma) = 1.2 in vertical and M(2)(sigma) = 2 in lateral direction.
Subject(s)
Lasers, Solid-State , Computer-Aided Design , Equipment Design , Equipment Failure Analysis , MiniaturizationABSTRACT
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.
