INTEGRATED CONTROL CIRCUIT FOR THERMALLY ACTUATED OPTICAL PACKET SWITCH

摘要

The advance in communication technology and growth of internet traffic have continuously driven the fast evolution of networks. Compared to the traditional optoelectronic switch, all-optical switch provides high throughput, rich routing functionalities, and excellent flexibility for rapid signal exchange in fiber optical network system. Among various all-optical switches, thermal actuated ring type switch provides the advantages of high accuracy, easy actuation, and reasonable switching speed. However, when scale up, thermal ring switch may encounter issues related to fabrication error, non-accurate wavelength response, and large terminal numbers in the control circuit. In this article we propose the employment of an integrated control circuit to compensate the fabrication error and tuning the wavelength response in a thermal actuated ring type optical switch. Additional functionalities can also be added in this circuit by tailoring externally the roundtrip loss or coupling constants of the ring. The design concept can be easily scaled up for large array format optical switch system without much change in the terminal numbers thanks to the three dimensional hierarchy of control circuit design, which effectively reduces the terminal numbers into the cubic root of the total control unit numbers. The integrated circuit has been designed, simulated, as well as fabricated, and demonstrated a decent performance with Free Spectral Range (FSR) equal to 1.5 nm at a wavelength of 1534 nm and center wavelength shift of the ring up to 0.3 nm for thermal actuated ring type optical switch.