Robert Blomquist

High-performance polymeric componentry for telecom and datacom applications

We review a polymeric waveguide technology developed to produce affordable high-performance optical components that address the needs of both the telecom and the datacom industries. We engineer advanced organic polymers that can be readily made into planar single- mode, multimode, and micro-optical waveguide structures of controlled numerical apertures and geometries. These materials are formed from highly crosslinked acrylate monomers with specific linkages that deter- mine properties such as flexibility, toughness, optical loss, and environ- mental stability. These monomers are intermiscible, providing for precise continuous adjustment of the refractive index over a wide range. In poly- mer form, they exhibit state-of-the-art loss values, suppressed polariza- tion effects, and exceptional stability, enabling their use in a variety of demanding applications. Waveguides are formed photolithographically, with the liquid monomer mixture polymerizing upon illumination in the UV via either mask exposure or laser direct writing. A wide range of rigid and flexible substrates can be used. The devices we describe include a va- riety of passive and thermo-optically active elements that achieve a va- riety of coupling, routing, and filtering functionalities. These devices can be either individually pigtailed and packaged components or they can be part of a massively parallel photonic integrated circuit on the multichip module (MCM), board, or backplane level.

Fluorinated acrylates in making low-loss, low-birefringence, and single-mode optical waveguides with exceptional thermo-optic properties

There is growing interest in the use of planar waveguide devices in telecommunications. Polymeric planar waveguide devices are of special interest in thermo-optic devices because of their high values for dn/dT. This paper details the possible choices in different photolithographic system that could be used in making such devices. This paper explains the benefits of using fluorinated acrylates in achieving low-loss waveguides with low birefringence. It also explains the unique benefits of fluorinated acrylates in making Bragg gratings.

Polymeric components for all-optical networks

All-optical networks that exhibit high speed, high capacity, scalability, configurability, and transparency are becoming a reality through the exploitation of the unique properties of fiber and integrated optics. An advanced polymeric waveguide technology was developed for affordable passive and active integrated optical elements that address the needs of these networks. We engineered high-performance organic polymers that can be readily made into photonic circuits of controlled numerical apertures and geometries. These materials are formed from highly-crosslinked acrylate monomers with specific linkages that determine properties such as flexibility, robustness, optical loss, thermal stability, and humidity resistance. These monomers are intermiscible, providing for precise continuous adjustment of the refractive index over a wide range. In polymer form, they exhibit state-of-the-art optical loss values, suppressed polarization effects, and exceptional environmental stability. A wide range of rigid and flexible substrates can be used. The devices we describe include demultiplexers, tunable wavelength filters, digital optical switches, and variable optical attenuators.

Thermo-optically active planar polymeric components for telecommunication applications

A key property that differentiates optical polymers from more conventional optical materials such as glass, is the rapid variation of the refractive index with temperature. This large difference in dn/dT can be leveraged to produce efficient thermo-optically active optical components. An advanced polymeric waveguide technology was developed for affordable thermo-optically active integrated optical devices that address the needs of the telecom industry. We engineered high-performance organic polymers that can be readily made into single-mode waveguide structures of controlled geometries and of modal profiles that closely match standard telecom glass fibers. These materials are formed from highly-crosslinked halogenated acrylate monomers with specific linkages that determined properties such as flexibility, toughness, optical loss, thermal stability, and humidity resistance. These monomers are intermiscible, providing for precise continuous adjustment of the refractive index over a wide range. In polymer form, they exhibit state-of-the-art loss values, suppressed polarization effects, and exceptional environmental stability. The devices we describe include thermally tunable Bragg-grating-based wavelength filters, thermally tunable arrayed-waveguide gratings, and digital optical switches.

Polymer Bragg gratings for wavelength division multiplexers

An advanced versatile, low-cost polymeric waveguide technology with Bragg gratings has been developed for filter applications in optical communications. Bragg gratings are photochemically formed in single mode polymeric waveguides using holographic techniques. The resulting gratings exhibit excellent filter characteristics; 99.997% reflectivity in a 2 cm grating, which corresponds to refractive index modulation of the order of 10-3, 0.2 nm width in the reflection peak at the 3 dB point in reflectivity, and no sidelobes in the reflection spectrum. The mechanism of the grating formation is discussed; its understanding enables us to enhance the filter characteristics of the gratings. The impact of temperature and humidity on the filter performance is also presented. The shift of the reflection maximum is 0.23 nm/ degree(s)C. The Bragg shift for a 90% change in relative humidity is 0.2 nm.