High-power Picosecond Pulse Generation Research Articles

High-Power Picosecond Pulse Generation Due to Mode-Locking With a Monolithic 10-mm-Long Four-Section DBR Laser at 920 nm

A 10-mm-long four-section distributed Bragg reflector laser with a double-quantum-well heterostructure at 920 nm was realized. A maximum optical pulse power of 3.6 W with a repetition rate of 4.1 GHz corresponding to the laser length was reached. The full-width at half-maximum of the pulses was 7 ps measured with an autocorrelator. A maximum pulse energy of 25 pJ was reached.

Passively Q-switched operation of a double contact tapered InGaAs/GaAs diode laser

High power picosecond pulse generation from a two-contact tapered two quantum well 980 nm InGaAs/GaAs diode laser is investigated using a passive Q-switching technique for the first time. Tail-free and single peak Q-switched pulses are obtained by applying reverse bias voltages in the range of 0 to −9 V to the absorber section of the device. Optical pulses with 41 ps (down to 29 ps) durations and peak powers in excess of 1.5 W are obtained in a well-defined single lobed far-field. Such an improvement in the optical pulses is attributed to a reduction of absorber recovery time.

Generation of high-power picosecond pulses from a gain-switched two-section quantum-well laser with a laterally tapered energy-storing section

We investigated experimentally the potential of generating high power gain-switched pulses from a two-section laser diode containing a laterally tapered energy-storing section and a ridge-waveguide modulation section. In particular, picosecond pulses with energies above 20 pJ and peak powers about 1 W were obtained by electrical pulse modulation at a repetition rate of 250 MHz. Large-signal operation up to the GHz range was also demonstrated. The lateral far-field pattern exhibited a single lobe subtending an angle near the diffraction limit, which showed that the lateral mode was well-controlled by the ridge-waveguide section.

Efficient generation of high-power picosecond pulses in a solid-state YAG : Nd system with a regenerative amplifier

A regenerative amplifier, capable of amplifying pulses from a cw YAG laser, was designed and built. The pulses were of 100 ps duration and were amplified to an energy of 19 mJ. The maximum energy of a pulse after its passage through an additional single-pass amplifier, 10 mm in diameter, reached 120 mJ. The power density of this radiation was 1014 W cm-2 when focused to form a spot 30 μm in size. The energy of a pulse converted to the second harmonic was 36 mJ.

Narrow line high power picosecond pulse generation in a multicontact distributed feedback laser using modified Q switching

High power bandwidth-limited picosecond pulses with peak powers in excess of 200 mW have been generated using multicontact distributed feedback laser diodes for the first time. The pulses have widths typically less than 10 ps, time-bandwidth products of as little as 0.24, and can be generated on demand at generator limited repetition rates of up to 140 MHz.

High-power picosecond pulse generation in GaAs multiquantum well phase-locked laser arrays using pulsed current injection

Gaussian shaped picosecond pulses as short as 62 ps have been obtained from an array of 10 phase-coupled multiquantum well GaAs lasers. Combined dc and 75 ps long current pulses from a comb generator were used. Single pulses were obtained with an average power of 50 mW at a 960 MHz repetition rate which corresponds to a peak power of 0.8 W. These pulse widths are in good agreement with a theory of pulse formation based on the carrier and photon density equations with the gain expanded in a power series in time to yield Gaussian pulses.

Generation of high-power picosecond pulses of 218–316 nm wavelengths

Generation, in a KDP crystal, of the sum frequencies of YAG:Nd3+ laser harmonics and the Stokes components of stimulated Raman scattering produced picosecond pulses of 218–316 nm wavelengths and 0.1–3 mJ energy.