The selection process leading to the development of a guest- host electro-optic material based on an amorphous polycarbonate is described. The optical loss at 1300 nm of this material system is under 2 dB/cm, which is the confidence limit of the slab measurement used. A Mach- Zehnder Modulator fabricated using the push-pull poling technique has a low switching voltage of 1.2V.
Optoelectronic devices based on organic materials are uniquely suited to applications requiring high rf bandwidth. There have been significant advances in lithium niobate technology, but fundamental frequency-sensitivity tradeoffs are generally required in device design. Using a guest-host electro-optic polymer system, we have demonstrated a Mach- Zehnder modulator with a switching voltage of 3.5 V and interaction length of 2.6 cm. Anisotropic V-groove etching for fiber attachment provides a path to low-cost packaging of these devices. Materials and process optimization are expected to enhance device performance, allowing more compact, sensitive devices. Issues related to electro-optic device development are discussed in this paper, and an update on our development of new chromophores for use in electro-optic polymers is given.
Polymer photonic modulators and switches offer several attractive features for space systems, including rf bandwidth of 50 GHz or higher, and the potential for high sensitivity and low cost. We have shown that polymer modulators experience little if any degradation (less than 2%) in the half-wave voltage due to total dose exposure of up to 5 MRad from a Co-60 source. An outgassing test at 125 degrees Celsius in vacuum for 24 hr resulted in a mass loss of less than 0.2% of the polymer material.
An approach to optical interconnect networks at the module level is presented that addresses the requirements imposed by electronic system manufacturing, such as thermal stability, low cost, and compatibility with standard electronic design, fabrication, and assembly processes. Research is presented on poled polyimide electro-optic materials with extended thermal stability, poled polyimide integrated optic switches acting as transmitters, and a demonstration of a CMOS-compatible optical interconnect.
We report the background leading to the development of the first all-polyimide system (cladding/core/cladding) suitable for fabrication of electro-optic waveguide devices on silicon substrates. The cladding layers are spun from a low optical loss, commercially available polyimide that is suitable for multilayer stacks. The electro-optic material consists of this same polyimide as host to a commercially available guest chromophore and is based upon our prior work on thermoplastic polyimides. The synthesis and purification of this chromophore and an analog is discussed. We also present the materials and process development methodology with the results for this polymer system and demonstrate it by fabrication of an all-polyimide Mach- Zehnder modulator operating at 830 nm. CMOS-compatible switching using a device based on the new material has been demonstrated.
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 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 electro-optic polymers for optical interconnection and present a review of some of the relevant progress to date in electro-optic polymer materials and devices. Development of an all-polyimide electro-optic polymer system (cladding/core/cladding) based entirely on commercially available components is described. An integrated optic Mach-Zehnder modulator was fabricated using this material system and used in a 200 Mbit/sec digital signal transmission optical interconnection demonstration. Lastly, a potential increase in electro-optic polymer integration density was illustrated by a proof of concept demonstration of three levels of waveguide structures on a single substrate.
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.
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.
We report on the recent development and initial test results of two electro-optic polymer based integrated optic devices for
optical interconnection applications. The first is an optical railtap for the distribution of many different optical signals from a
single CW laser diode, and the second is a traveling wave Mach-Zehnder integrated optic modulator, which was modulated at
frequencies up to 8 GHz. Electro-optic polymer materials supplied by Akzo Research, By, were used in both devices.