An approach for Si/Si wafer bonding based on boride-solution treatment was presented. The bonding energy is higher
than the Si fracture energy by annealing at 180°C. The properties of the bonded structures were studied in terms of the
interface shape, electrical and optical characteristic through scanning electron microscopy (SEM), interface I-V curve, and
so on. In this method, the surfaces of two wafers are active by Boride solution, and then following a thermal annealing
process. The bonding strength was found to be sufficiently high and could withstand the subsequent etching and
polishing procedures of the bonded wafers. This low temperature wafer bonding technology can be used in Optic
Electronics Integrated Circuit and this technology with potential to meet a broad range of future telecommunication and
computing systems' needs.
Integrated optical demultiplexing and receiving device based on one-mirror-inclined three-mirror cavity (OMITMiC) structure, or OMITMiC wavelength-selective photodetector, is a kind of novel integrated multifunction optoelectronic device which was proposed in 1996 and first realized with GaAs-based materials for short wavelength (less than 1μm) operation in 2001. Recently, after great efforts on developing controllable self-retreating dynamic mask (CSRDM) wet etching method for InP-based epitaxial layer and low temperature InP/GaAs wafer bonding technique, such a device operating at long wavelength region (1550nm) had also been successfully demonstrated and the measurement results shown that it features high-speed (12GHz with a mesa area of 40×36 μm<sup>2</sup>), high quantum efficiency (66%~78.4%), ultra-narrow spectral linewidth (0.6 nm) and wide range tuning (more than 10 nm ) simultaneously. In addition, a long wavelength monolithic OMITMiC photodetector with GaInNAs absorption layer has also been demonstrated. These achievements could have a significant impact on wavelength-division-multiplexed (WDM) optical fiber transmission systems and networks.
We demonstrate a wavelength-selective photodetector that combines a Fabry-Perot filtering-cavity (FPC) with a taper absorption-cavity (TAC). The taper cavity shows non-resonant effect but exhibits absorption enhancement effect, so that high-speed, high quantum efficiency, wide tuning range and ultra-narrow spectral linewidth can be achieved simultaneously. Device performance was theoretically investigated by including key factors such as taper angle, finite-size diffracting-beam input, and lateral walk-off in the taper cavity. The device was fabricated by bonding a GaAs-based FPC, which can be tuned via thermal-optic effect, with an InP-based TAC. The experiment results of the devices were reported in another paper.
A kind of GaAs-based F-P(Fabry-Perot) cavity filter was presented. Its structure and tunability were analysed theoretically. Numerical simulation shows transmitted centre wavelength of the filter is 1.55μm, FWHM is 1.8nm and 0.6nm with 17 and 23 pairs of DBR respectively, a red shift of 7.2nm with temperature change of 100K, transmissivity almost keeps unchanged during tuning, and tuning wavelength is linear to temperature change. Further, long-wavelength-absorbed integrated photodetectors based on this filter structure was fabricated. Experimental results show a tuning wavelenghth of 10.2nm with power change of 200mW applied to the device, FWHM of about 0.6nm, and 4% quantum efficiency fluctuation during tuning. Good agreement with the simulation has been achieved.
We design a new Dynamic Power Equalization system by using OCM and DCE technology. The experiment results show that the new system has faster equalization speed and higher equalization precision than existing equipment. The equalization time is less than 200ms, and the precision is higher than 0.5dB.
A novel InP-based micromechanied tunable photodetector with the structure of OMITMC (One-Mirror-Inclined Three-Mirror-Cavity)is presented. The tuning characteristic of the device is analysed in the way of electrical actuation. Through simulation of the filter transmission spectra and the quantum efficiency, the characteristics of high tunability, narrow bandwidth and high quantum efficiency are analysed. As a result, the photodetector is tuned with 30nm,with a quantum efficiency of 59% and a linewidth of 1.2nm, when actuated by 10 volts.