C. Y. Chen

Comparison of four-wave mixing in quantum dots and quantum wells for wavelength conversion

We experimentally investigate wavelength conversion in quantum-dot and quantum-well optical amplifiers via four-wave mixing. Our results show superior conversion efficiency in a quantum dot device compared to a quantum well device with identical gain.

25-Gbaud PAM4 and 1300nm directly modulated laser diode using low parasitic electrodes for long-distance transmission

A new high-speed 1300nm directly modulated DFB laser with high power has been demonstrated. With low parasitic capacitance of coplanar electrodes, 25mW has been obtained in a long waveguide, while maintaining high-speed performance. 50Gb/s PAM-4 modulation over 35km transmission without amplification has been realized with low degradation.

Differential absorption spectroscopy for vertically coupled InGaAs quantum dots of p-type modulation doping

We report the differential absorption (Deltaalpha) spectra of the vertically coupled triple-layer InGaAs quantum dots (QDs) at different reverse bias. The results show that the decrease of spacer layer thickness increases the differential absorption. Adding p-type modulation doping further increases the differential absorption amplitude at ground state.

Multiple lasing lines from deep-etched photonic crystal of asymmetric muliple quantum wells

A slab photonic crystal (PhC) laser was fabricated on InP substrate. The wafer consists of p-i-n laser epitaxial structure with asymmetric InGaAs/InGaAlAs multiple quantum wells. The deep-etched PhC laser of 2.76 mum-thick was achieved by ICP-RIE dry etching process using Cl2+SiCl4+CH4 mixture. Lasing spectrum shows three lasing modes at lambda = 1505, 1535, and 1551 nm, respectively.

In(Ga, Al)As quantum dot/wire growth on InP

The authors have investigated the growth of dots/wires on InP substrates by tuning the In(Ga, Al)As compositions for dots/wires and buffer layers. Dots and wires with compositions including InAs, In0.95Al0.05As, In0.95Ga0.05As, and In0.90Ga0.10As were grown on In0.53Ga0.26Al0.21As and In0.52Al0.48As buffer layers, respectively. In(Ga)As nanostructure grown on InAlAs ternary buffer layer forms elongated dots along the [0-11] direction. On the other hand, In0.95Ga0.05As and In0.90Ga0.10As nanostructures grown on InGaAlAs buffer layer form quantum wire arrays of high uniformity. The In0.90Ga0.10As quantum wires have a photoluminescence spectrum of emission peak at λ∼1680nm and a narrow full width at half maximum of 65meV at 10K. For the growth of In0.95Al0.05As nanostructures, dot formations are observed on the InAlAs and InGaAlAs buffer layers.

Emission and absorption polarization in InGaAs multiple quantum dots layers of different spacer layer thickness

Triple-layer InGaAs QDs of different spacer layer thickness are characterized by polarized electroluminescence and photocurrent spectroscopy. The results show that the decease of spacer layer thickness increases the TE/TM insensitivity.

Structural and Optical Characteristics of Strain-mediated InGaAs Quantum Dots

Self-assembled In_xGa_1-xAs quantum dots, with In(Ga)As capping layers to mediate the strain distribution were studied by x-ray reciprocal space mapping, TEM, and PL. The In_0.75Ga_0.25As QDs capped with In_0.1Ga_0.9As has a PL emission at lambda = 1.31 mum.

Surface morphology and photoluminescence for InAs quantum dots of different growth temperature and capping layer

InAs QDs of eight different grown temperatures are measured by AFM and photoluminescence measurement. PL emission peak at 1.306 mum was obtained for InAs QDs with In0.1Ga0.9As capping layer grown at 510degC

/spl lambda/ = 1.3 /spl mu/m high density InGaAs/GaAs quantum dots grown by molecular beam epitaxy

In_xGa_1-xAs (x=0.5-0.75) QDs of high density of 1.3 times 10¹¹ cm^-2 and uniform size (diameter ~ 23-nm and height ~ 4-nm) were obtained by MBE. lambda = 1.3 mum emission was observed for In_0.65Ga_0.35As QDs capped with In_0.1Ga_0.9As

Broad and flat emission spectrum from InGaAs/InGaAlAs asymmetric multiple quantum wells: effect of well-width and modulation-doping profiles

Asymmetric InGaAs/InGaAlAs multi-quantum wells exhibit a = 1.55 mum broad and flat emission spectrum with 3-dB bandwidth up to 2500 Aring. Emission spectra and laser diodes by the effects of well-width and modulation-doping profiles are presented