Compound-semiconductor-based photonic devices, including lasers and modulators, directly grown and on-chip
integrated on Si substrates provide a promising approach for the realization of optical interconnects with CMOS
compatibility. Utilizing quantum dots as efficient dislocation filters near the GaAs-Si interface, for the first time, we
demonstrated high-performance InGaAs/GaAs quantum dot (QD) lasers on silicon with a relatively low threshold
current (Jth = 900 A/cm2), large small-signal modulation bandwidth of 5.5 GHz, and a high characteristic temperature (T0
= 278 K). The integrated InGaAs QD lasers with quantum well (QW) electroabsorption modulators, achieved through
molecular beam epitaxy (MBE) growth and regrowth, exhibit a coupling coefficient greater than 20% and a modulation
depth ~100% at 5 V reverse bias. We achieved the monolithic integration of amorphous and crystalline silicon
waveguides with quantum dot lasers by using plasma-enhanced-chemical-vapor-deposition (PECVD) and membrane
transfer, respectively. Finally, preliminary results on the integration of QD lasers with Si CMOS transistors are
We have studied the growth and characteristics of self-organized InGaAs/GaAs quantum dot lasers and their
monolithic integration with waveguides and quantum well electroabsorption modulators on Si. Utilizing multiple layers
of InAs quantum dots as effective dislocation filters near the GaAs-Si interface, we have demonstrated high performance
quantum dot lasers grown directly on Si that exhibit, for the first time, relatively low threshold current (Jth = 900 A/cm2),
large characteristic temperature (T0 = 278 K), and output slope efficiency ( ⩾0.3 W/A). Focused-ion-beam milling has
been used to form high-quality facets for the cavity mirror and coupling groove of an integrated laser/waveguide system
on Si. We have also achieved a groove-coupled laser/modulator system on Si that exhibits a coupling coefficient greater
than 20% and a modulation depth of ~ 100% at 5 V reverse bias.
We have investigated the molecular beam epitaxial growth and characteristics of self-organized InGaAs quantum dot lasers grown directly on silicon utilizing thin (≤2 μm) GaAs buffer layers and quantum dot layers as dislocation filters. Both the photoluminescence intensity and linewidth from quantum dots grown on silicon are comparable to those from similar dots grown on GaAs substrates. Cross-sectional transmission electron microscopy studies indicate that defect-free quantum dots and low defect density quantum dot active regions can be achieved. The best devices are characterized by relatively low threshold current (Jth ~ 900 A/cm2), high output power (> 150 mW), large characteristic temperature (T0 = 244 K) and constant output slope efficiency (≥ 0.3 W/A) in the temperature range of 5 to 95 °C.
We have investigated the molecular beam epitaxial growth and characteristics of self-organized In(Ga)As quantum dot lasers grown on GaAs and silicon. Utilizing the techniques of tunnel injection and acceptor-doping of quantum dots, we have achieved high performance 1.3 μm InAs quantum dot lasers on GaAs, which exhibit Jth=180 A/cm2, T0=∞, dg/dn≈1×10-14 cm2, f-3dB=11 GHz, chirp of 0.1 Å and zero α-parameter. Utilizing thin (⩽ 2 μm) GaAs buffer layers and quantum dots as dislocation filters, we have demonstrated room-temperature operational In0.5Ga0.5As quantum dot lasers grown directly on silicon, which are characterized by relatively low threshold current (Jth ~ 900 A/cm2), high output power (> 150 mW), large characteristic temperature (T0 = 244 K) and constant output slope efficiency (⩾ 0.3 W/A) in the temperature range of 5 to 95 °C.
Today's design-manufacturing interfaces have only minimal information exchange. Lack of information on either side leads to under-performance due to too much guardbanding, and increased mask cost and increased turnaround time due to over-correction. In this work we present techniques that simultaneously utilize design and manufacturing information to improve mask quality and reduce mask cost.
Photonic microring resonators have great potential in the application of highly sensitive label-free biosensors due to high Q-factor resonances. Design consideration, device fabrication techniques, methods to increase the resonance Q-factors, and preliminary experimental data on biomolecular detections are discussed in this paper.