Heinz Jaeckel

Very high-power (425 mW) AlGaAs SQW-GRINSCH ridge laser with frequency-doubled output (41 mW at 428 nm)

A very high-power AlGaAs single-quantum-well graded-index separate confinement heterostructure (GRINSCH) ridge laser operating in a diffraction-limited fundamental transverse mode up to 360 mW at a wavelength of 856 nm is presented. The maximum power output of the laser reached 425 mW, limited by thermal saturation of the device and not by catastrophic optical mirror damage. These lasers exhibit very high power levels and show excellent reliability at high output power levels. The extremely high, continuous-wave (CW) fundamental mode power combined with very low-intensity and optical phase distortion as well as low astigmatism render this ridge waveguide laser suitable for optical storage systems, printers, and direct frequency doubling. These devices have been successfully used for direct-frequency doubling of their output in a resonant KNbO/sub 3/ cavity yielding 41 mW of blue radiation at 428 nm. >

Blue light generation by resonator‐enhanced frequency doubling of an extended‐cavity diode laser

Frequency doubling of diode laser radiation was achieved by operating an AR‐coated diode laser in an extended laser cavity which contained a monolithic potassium niobate frequency doubling resonator as an intracavity element. Extended cavity operation ensured that the diode laser would oscillate only at frequencies that were resonant with the intracavity resonator. A diffraction grating was used to ensure single mode oscillation at the wavelength needed for noncritically phase‐matched second harmonic generation. At 100 mA of injection current to the GaAlAs diode laser, 14 mW of 429 nm light were produced.

Beam properties of AlGaAs power lasers with high-quality etched mirrors

High-quality etched mirrors for AlGaAs/GaAs power lasers for applications in optical storage have been fabricated by chemically assisted ion-beam etching (CAIBE). In order to ensure flat mirror facets of the ridge-waveguide lasers, a flared-waveguide end section is used. This results in a very slight mirror roughness of approximately 20 nm across the beam cross section, and yields excellent beam properties allowing diffraction-limited focusing up to 50-mW output power.<<ETX>>

Generation of 425‐nm light by waveguide frequency doubling of a GaAlAs laser diode in an extended‐cavity configuration

A blue output power of 1.2 mW at 425 nm was generated using a periodically poled KTP waveguide for frequency doubling of a grating tuned, extended‐cavity laser containing an antireflection‐coated GaAlAs SQW‐GRINSCH laser diode as the gain element. A normalized conversion efficiency of 127%/W cm2 was achieved in the extended‐cavity configuration.

Indium migration and controlled lateral bandgap variations in high-power strained layer InGaAs-AlGaAs lasers grown on nonplanar substrates

Strained single quantum well (SQW) InGaAs-AlGaAs graded-index separate confinement heterostructure (GRINSCH) lasers were grown by molecular beam epitaxy over nonplanar

A 40-Gb/s, digitally programmable peaking limiting amplifier with 20-dB differential gain in 90-nm CMOS

A 40-Gb/s differential CMOS limiting amplifier in standard 90-nm technology is presented. The circuit dissipates as little as 80 mW from a 1 V power supply and has a differential gain of 20 dB. It can drive data at 40 Gb/s into multiple sampling circuits with a total input capacitance as high as 300 fF. The amplifier features a digitally programmable load resistor for the differential stages to control gain-peaking intensity. This can be used to cancel process variations or for active channel-compensation schemes. The output common mode voltage and circuit bias are controlled by a replica stage. The circuit occupies 0.033 mm2 of silicon real estate

A DC-to-44-GHz 19dB Gain Amplifier in 90nm CMOS Using Capacitive Bandwidth Enhancement

A DC-to-44GHz amplifier with 19dB differential gain in a standard 90nm CMOS technology is presented. Capacitive bandwidth and group-delay enhancements are combined with series peaking in a shunt-peaking amplifier. The circuit occupies 0.02mm2 and dissipates 57mW at 1V

Very high power (500mW) AlGaAs SQW grinsch ridge laser with frequency doubled output (40mW at 428nm)

We demonstrate a very high-power AlGaAs single quantum well GRINSCH ridge laser operating in a diffraction- limited fundamental transverse mode up to 360 mW at a wave- length of 856 nm. The maximum power output of the laser reached 425 mW and was limited by thermal saturation of the device and not by catastrophic optical mirror damage. These lasers not only exhibit very high power levels, but also show excellent reliability at high output power levels. The extremely high, CW fundamental mode power combined with very low- intensity and optical low-phase distortion as well as low astig- matism render this ridge waveguide laser very suitable for op- tical storage systems, printers, and direct frequency doubling. These devices have been successfully used for direct frequency doubling of their output in a resonant KNh03 cavity yielding 41 mW of blue radiation at 428 nm.