Fabrication of 1.55-mu m Si-based resonant cavity enhanced photodetectors using sol-gel bonding

In this work, a novel bonding method using silicate gel as the bonding medium was developed to fabricate an InGaAs narrow-band response resonant cavity enhanced photodetector on a silicon substrate. The bonding was performed at a low temperature of 350 degreesC without any special treatment on bonding surfaces and a Si-based narrow-band response InGaAs photodetector was successfully fabricated, with a quantum efficiency of 34.4% at the resonance wavelength of 1.54 mum, and a full-width at half-maximum of about 27 nm. The photodetector has a linear photoresponse up to 4-mW optical power under 1.5 V or higher reverse bias. The low temperature wafer bonding process demonstrates a great potential in device fabrication.

Design and fabrication of 1.06 mu m resonant-cavity enhanced reflective modulator with GaInAs/GaAs quantum wells

A resonant-cavity enhanced reflective optical modulator is designed and frabricated, with three groups of three highly strained InGaAS/GaAs quantum wells in the cavity, for the low voltage and high contrast ratio operation. The quantum wells are positioned in antinodes of the optical standing wave. The modulator is grown in a single growth step in an molecular beam epitaxy system, using GaAs/AIAs distributed Bragg reflectors as both the top and bottom mirrors. Results show that the reflection device has a modulation extinction of 3 dB at -4.5 V bias.

High-performance 1.55 mu m low-temperature-grown GaAs resonant-cavity-enhanced photodetector

A 1.55 mu m low-temperature-grown GaAs (LT-GaAs) photodetector with a resonant-cavityenhanced structure was designed and fabricated. A LT-GaAs layer grown at 200 degrees C was used as the absorption layer. Twenty- and fifteen-pair GaAs/AlAs-distributed Bragg reflectors were grown as the bottom and top mirrors. A responsivity of 7.1 mA/W with a full width at half maximum of 4 nm was obtained at 1.61 mu m. The dark current densities are 1.28x10(-7) A/cm(2) at the bias of 0 V and 3.5x10(-5) A/cm(2) at the reverse bias of 4.0 V. The transient response measurement showed that the photocarrier lifetime in LT-GaAs is 220 fs. (c) 2006 American Institute of Physics.

Fabrication of 1.55μm Si-Based Resonant Cavity Enhanced Photodetectors

A novel bonding method using silicate gel as bonding medium is developed.High reflective SiO2/Si mirrors deposited on silicon substrates by e-beam deposition are bonded to the active layers at a low temperature of 350℃ without any special treatment on bonding surfaces.The reflectivities of the mirrors can be as high as 99.9%.A Si-based narrow band response InGaAs photodetector is successfully fabricated,with a quantum efficiency of 22.6% at the peak wavelength of 1.54μm,and a full width at half maximum of about 27nm.This method has a great potential for industry processes.

Fabrication of silicon-on-reflector for Si-based resonant-cavity-enhanced photodetectors

A novel silicon-on-reflector substrate for Si-based resonant-cavity-enhanced photodetectors has been fabricated by using Si-based sol-gel and smart-cut techniques. The Si/SiO2 Bragg reflector is controlled in situ by electron beam evaporation and the thickness can be adjusted to get high reflectivity. The reflectance spectra of the silicon-on-reflector substrate with five pairs of Si/SiO2 reflector have been measured and simulated by transfer matrix model. The reflectivity at operating wavelength is close to 100%. Based on the silicon-on-reflector substrate, SiGe/Si multiple quantum wells resonant-cavity-enhanced photodetectors for 1.3 mu m wavelength have been designed and simulated. Ten-fold enhancement of the quantum efficiency of resonant-cavity-enhanced photodetectors compared with conventional photodetectors is predicted.

Recent progresses of SOI-based photonic devices - art. no. 60201R

SOI (Silicon on Insulator) based photonic devices, including stimulated emission from Si diode, RCE (Resonant Cavity Enhanced) photodiode with quantum structure, MOS (Metal Oxide Semiconductor) optical modulator with high frequency, SOI optical matrix switch and wavelength tunable filter are reviewed in the paper. The emphasis will be played on our recent results of SOI-based thermo-optic waveguide matrix switch with low insertion loss and fast response. A folding re-arrangeable non-blocking 4x4 matrix switch with total internal reflection (TIR) mirrors and a first blocking 16 x 16 matrix were fabricated on SOI wafer. The extinction ratio and the crosstalk are better. The insertion loss and the polarization dependent loss (PDL) at 1.55 mu m increase slightly with longer device length and more bend and intersecting waveguides. The insertion losses are expected to decrease 2-3 dB when anti-reflection films are added in the ends of the devices. The rise and fall times of the devices are 2.1 mu s and 2.3 mu s, respectively.

On the performance analysis and design of a novel shared-layer integrated devices using RCE-p-i-n-PD/SHBT - art. no. 67820J

We have explored the shared-layer integration fabrication of an resonant-cavity-enhanced p-i-n photodector (RCE- p-i-n-PD) and a single heterojunction bipolar transistor (SHBT) with the same epitaxy grown layer structure. MOCVD growth of the different layer structure for the GaAs based RCE- p-i-n-PD/SHBT require compromises to obtain the best performance of the integrated devices. The SHBT is proposed with super-lattice in the collector, and the structure of the base and the collector of the SHBT is used for the RCE. Up to now, the DC characteristics of the integrated device have been obtained.

Recent progresses of Si-based photonics in chinese main land

Si-based photonic materials and devices, including SiGe/Si quantum structures, SOI and InGaAs bonded on Si, PL of Si nanocrystals, SOI photonic crystal filter, Si based RCE (Resonant Cavity Enhanced) photodiodes, SOI TO (thermai-optical) switch matrix were investigated in Institute of Serniconductors, Chinese Academy of Sciences. The main results in recent years are presented in the paper. The mechanism of PL from Si NCs embedded in SiO2 matrix was studied, a greater contribution of the interface state recombination (PL peak in 850 similar to 900 nm) is associated with larger Si NCs and higher interface state density. Ge dots with density of order of 10(11) cm(-2) were obtained by UHV/CVD growth and 193 nm excimer laser annealing. SOI photonic crystal filter with resonant wavelength of 1598 nm and Q factor of 1140 was designed and made. Si based hybrid InGaAs RCE PD with eta of 34.4% and FWHM of 27 nut were achieved by MOCVD growth and bonding technology between InGaAs epitaxial and Si wafers. A 16x16 SOI optical switch matrix were designed and made. A new current driving circuit was used to improve the response speed of a 4x4 SOI rearrangeable nonblocking TO switch matrix, rising and failing time is 970 and 750 ns, respectively.

Experimental study on tunable external cavity photodetectors

In this paper, an experiment on tunable resonant cavity enhanced (RCE) photodetector with external cavity is reported. It is the first time to realize a tunable RCE photodetector in China. A tuning range about 10 nm has been obtained and further extension is expected. Corresponding theoretical analysis and discussions are presented. (C) 2000 Elsevier Science B.V. All rights reserved.

Magnetic resonant cavity composing of a three layered plasmonic nanostructure

The magnetic-type plasmon resonant of a metal-dielectric-metal nanocavity working at the wavelength of 1.55 mu m is explored, in which the upper layer is periodically patterned with metallic nanostrip arrays. In the dielectric film layer, the magnetic energy intensity is enhanced about 1700 times when irradiated with a p-polarized plane wave. We numerically studied the dispersion of the modes and the Q-value of this periodic cavity arrays. Q value is estimated about 18 and still has room for further improvement. It provides a new type of nanocavity that exhibits a strong magnetic response.

A GaAs-Based MOEMS Tunable RCE Photodetector with Single Cantilever Beam

A GaAs-based micro-opto-electro-mech anical-systems(MOEMS) tunable resonant cavity enhanced(RCE)photodetector with a continuous tuning range of 31nm under a 6V tuning voltage is demonstrated. The single cantilever beam structure is adopted for this MOEMS tunable RCE photodetector. The maximum and minimum peak quantum efficiency during the tuning are 36.9 % and 30. 8 %, respectively. The maximum and minimum full-width-at-halfmaximum (FWHM) are 20nm and 14nm,respectively. The dark current density is 7.46A/m2 without bias.

The Incident Angle Dependence of Quantum Efficiency of GaAs Based RCE Photodetectors

The theoretical analysis and experimental measurement on the incident angle dependence of quantum efficiency of GaAs based resonant cavity enhanced (RCE) photodetector is presented. By changing the angle of incoming light, about 40 nm wavelength variation of peak quantum efficiency is obtained. The peak quantum efficiency and optical bandwidth at different mode corresponding to different angle incidence is characterized with different absorption dependence on wavelength. The convenient angle tuning of resonant mode will be helpful to relax the strict constraint of RCE photodetector to light source with narrow emission spectrum such applications in space optical detections and communications.

Long-wavelength Si-based MQW photodetectors for application in optical fiber communication

Si-based SiGe/Si strained MQW long-wavelength photodetectors (PD) with cycle type (Ring Shape) waveguide (CWG) and resonant-cavity-enhanced (RCE) structure have been investigated for the first time for improving the quantum efficiency and response time. The results show that the responsivities are higher than that of conventional PD with a same Ge content reported previously. In addition, RCE-PD has an obvious narrow band response with FWHM less than 6nm.

Analysis for the angle dependence of GaAs based RCE photodetectors

The theoretical analysis and experimental measurement on the angle dependence of quantum efficiency of GaAs based resonant cavity enhanced (RCE) photodetector is presented. By changing the angle of incoming light, about 40mn wavelength variation of peak quantum efficiency has been experimentally obtained. The peak quantum efficiency and optical bandwidth at different mode corresponding to different angle incidence have been characterized with different absorption dependence on wavelength. The convenient angle tuning of resonant mode will be helpful to relax the strict constraint of RCE photodetector to light source with narrow emission spectrum while especially applied in space optical detections and communications.

Investigation on integrated high speed DFB light source and narrow bandwidth RCE photodetector for WDM fiber communication network application

Electroabsorption (EA) modulator integrated with partially gain coupling distributed feedback (DFB) lasers have been fabricated and shown high single mode yield and wavelength stability. The small signal bandwidth is about 7.5 GHz. Strained Si1-chiGechi/Si multiple quantum well (MQW) resonant-cavity enhanced (RCE) photodetectors with SiO2/Si distributed Bragg reflector (DBR) as the mirrors have been fabricated and shown a clear narrow bandwidth response. The external quantum efficiency at 1.3 mum is measured to be about 3.5% under reverse bias of 16 V. A novel GaInNAs/GaAs MQW RCE p-i-n photodetector with high reflectance GaAs/ALAs DBR mirrors has also been demonstrated and shown the selectively detecting function with the FWHM of peak response of 12 nm.