We developed a design technique for a photonics-electronics convergence system by using an equivalent circuit of optical devices in an electrical circuit simulator. We used the transfer matrix method to calculate the response of an optical device. This method used physical parameters and dimensions of optical devices as calculation parameters to design a device in the electrical circuit simulator. It also used an intermediate frequency to express the wavelength dependence of optical devices. By using both techniques, we simulated bit error rates and eye diagrams of optical and electrical integrated circuits and calculated influences of device structure change and wavelength shift penalty.
Silicon (Si) photonic wire waveguides provide a compact photonic platform on which passive, dynamic, and active photonic devices can be integrated. This paper describe the demonstrations of several kinds of integrated photonic circuits. The platform consists of Si wire, silicon-rich Si dioxide (SiOx) and Si oxinitride (SiON) waveguides for passive devices and a Si rib waveguide with a p-i-n structure and a germanium (Ge) device formed on Si slab for active devices. One of the key technologies for the photonic integration platform is low temperature fabrication because a back-end process with high temperature may damage active and electronic devices. To overcome this problem, we have developed electron cyclotron resonance chemical vapor deposition as a low-temperature deposition technique. Another key technology is polarization manipulation for reducing polarization dependence. A polarization diversity circuit is fabricated by applying Si wire and SiON integration. The polarization-dependent loss of the diversity circuit is less than 1 dB. Moreover we have developed several kinds of integrated circuit including passive, dynamic and active devices. Ge photodiodes are monolithically integrated with an SiOx-arrayed waveguide grating (AWG). We have confirmed that the operation speed of the integrated Ge photodiode is over 22 Gbps for all 16 channels. Variable optical attenuators (VOAs) fabricated on the Si p-i-n rib waveguides and an AWG based on the SiOx waveguide are integrated successfully. The total size of 16-ch-AWG-VOAs is 15 8 mm2. The device has already been made polarization independent. Furthermore electronic circuits are successfully mounted on the integrated photonic device by using flip-chip bonding.