Edward S. Binkley

Electro-optic polymers for optical interconnects

Glassy nonlinear optical polymers can be processed into channel waveguides. When poled, the channels become electrooptic and can switch and modulate light. Using lithographic and machining techniques familiar to the chip industry, it should be possible to integrate large numbers of electrooptic switches into a board-level package or module, and thus provide the additional benefits of active switching and reconfiguration to passive hybrid optical interconnect modules. Some of the properties of the materials, some process methods, and potential applications in optical interconnection are described.

Poled polyimides as thermally stable electro-optic polymer

Using polyimide as host in a guest-host electro-optic thin film a thermally stable poled electro- optic response is demonstrated at temperatures at 150 degree(s)C and 300 degree(s)C. A coplanar-electrode poling geometry is used so that the guest molecular alignment between the electrodes is coincident with the free volume of the host. Electric field poling during curing process including imidization (170 - 230 degree(s)C) and densification (340 - 380 degree(s)C) accounts for the highly thermally stable electro-optic response.

Development of highly active, thermally stable chromophores and polymers for electro-optic applications

We have developed two classes of highly efficient and thermally stable nonlinear optical chromophores using fused-thiophene and bithiophene as conjugating units. Experimental studies indicate that the use of fused-thiophene or bithiophene as a (pi) conjugating bridge provides an excellent tradeoff between nonlinearity and thermal stability. In addition to the chromophore developments, we have employed new synthetic methodologies to obtain thermally stable poled polyimides.

Progress on heteroaromatic chromophores in high-temperature polymers for electro-optic applications

We have developed several classes of thermally stable nonlinear optical chromophores based on the combination of efficient thiophene conjugating units and novel electron-donating and electron-accepting functional groups. The incorporation of these chromophores into high temperature polymers produces high linear electro-optic coefficients and long-term thermal stability at elevated temperatures. Active Mach-Zehnder interferometers with a V(pi) phase shift of 50 volts and low attenuation (< 2 dB/cm) were fabricated. Thermal baking of the poled device demonstrated no change in activity after 30 minutes at 230 degree(s)C.

Electro-optic polymer devices for optical interconnects

Electro-optic polymers exhibit many useful properties for distribution and routing of light on optical multilayer boards and modules. With the development of more robust materials it should soon be possible to use these materials to provide high-density interconnects at significant power savings and with reduced noise at frequencies above 100 MHz. We review the research toward creating new materials and devices for applications to packaging technology.

Organic electro-optic devices for optical interconnnection

The exceptional electro-optic properties of poled polymer films, coupled with the power and flexibility of thin film fabrication and photolithographic processing, may make possible a new class of integrated optic systems: photonic large scale integration (PLSI). PLSI systems are characterized by the hybrid integration of electronic and photonic devices, combining the processing power of VLSI with a dense, high bandwidth, photonic interconnection and switching network in a single, large format, package. In this paper, we describe the potential applications and benefits of PLSI and present a review of some of the relevant progress to date in electro-optic polymer materials and devices, including the demonstration of polymer switch based 100 Mbit/sec digital signal transmission for optical interconnection and a 20 GHz electro-optic polymer modulator.

Active multilayer optical backplanes

We shall discuss our work in using thin-film optical polymers to incorporate guided-wave optical data and signal links in electronic systems 1.