Abstract :
Laser induced quantum well intermixing (QWI), using CW and pulsed Nd:YAG lasers, is a powerful photonic integration technology. The bandgap of the intermixed alloy is larger than that of the original QW structure and the refractive index is modified, thus providing a route to the formation of low loss waveguides, laser structures, gratings and other optical components. Results from the InP and GaAs systems, covering wavelengths from 1.5 μm to the visible, are presented. The photo-absorption induced disordering (PAID) and pulsed-PAID (P-PAID) QWI techniques are described and their application to several material systems reported. Despite their apparent similarities, the underlying physical processes involved in the two techniques are very different. PAID is essentially the result of sample heating through single photon absorption, whilst P-PAID is the result of bond breaking through rapid transient heating through multi-photon processes. In both cases, bandgap tuned optoelectronic devices have been fabricated in the intermixed material, so demonstrating that the material is of high electrical and optical quality
Keywords :
III-V semiconductors; diffraction gratings; energy gap; gallium arsenide; indium compounds; integrated optics; integrated optoelectronics; laser materials processing; multiphoton processes; optical fabrication; optical waveguides; photothermal effects; quantum well lasers; refractive index; semiconductor quantum wells; 1.5 mum to 700 nm; AlGaInAs-AlGaAs; CW lasers; GaAs; GaAs-AlGaAs; GaInAs-GaInAsP; GaInAsP; InP; bandgap; bandgap tuned optoelectronic devices; bond breaking; gratings; high electrical quality; high optical quality; intermixed alloy; intermixed material; laser induced quantum well intermixing; laser structures; low loss waveguides; multi-photon processes; optical components; optoelectronic devices; photo-absorption induced disordering; photonic integration technology; physical processes; pulsed Nd:YAG lasers; pulsed-PAID; rapid transient heating; refractive index; sample heating; single photon absorption; Heating; Optical devices; Optical materials; Optical pulses; Optoelectronic devices; Photonic band gap; Power lasers; Quantum well lasers; Refractive index; Waveguide lasers;
