Tech Briefs

POF technology has much to offer to the device industry.

Plastic Optic Fiber (POF) is an established, continually evolving technology available since the early 1980s. From the outset, it was a technology not highly visible for years. At times, it was utilized as a media product within another product, attached to a variety of opto-couplers or light sources. Primarily it was intended to transmit information of functional digital data transfer for many sensing concepts and for small form illumination. In addition, the very nature of POF technology brings to engineering many of the attributes of glass fiber optic technology. But, the extensive functions of POF lend themselves to much wider product uses including medical instruments, data control and networks, automotive use, and a host of industrial concepts. At the same time, POF offers low-cost solutions for short-range communications, and a majority of defined illumination requirements.

POF is made from PMMA (polymethyl methacrylate), more commonly known as acrylic. Structurally similar to glass fiber optics, it incorporates a unique core along with cladding layers. Importantly, POF differentiates itself by overall core size, limited cladding thickness, and a large light acceptance angle. Its thin, outer layer polymer cladding has a lower refractive index than the core, thus fully retaining transmitted light within the fiber, effectively operating in the visible wavelength range of 400 to 760nm. Of interest are fiber products available in multiple grades and diameters so that end products may easily be “designed-in” to achieve engineering requirements. However, caution should be exercised when heat is present and if long distance transmission is utilized.

ESKA™ POF is one plastic optic fiber available. It delivers total EMI/RFI immunity, has a wide 100Mbit bandwidth soon operable at 1Gbt levels, provides superior flexibility, and other mechanical strengths. It may be placed in offset and separated positions with operating temperatures ranging from -55°C to +105°C. These attributes, combined with no polishing requirements, few handling concerns, and ease of combining with other low cost components, enhances the POF position as an ideal inexpensive fiber consideration. POF is also in compliance with a number of standards, is FDA approved, and meets specific UL standards where applicable. With so many positive uses and advantages, there is no question why POF is now included in many added-value design concepts: combining lenses with fiber, fiber arrays, light-pipes, special assemblies, and processes.

One significant and innovative offering from Mitsubishi International is (POF) Fiber-Torch™, a side-glow fiber light pipe suited for critical, in situ medical use. Functionally, it enables launched light to be evenly bright, glowing along the length of a fiber, not just at the end. It is the result of high accuracy processing, which removes the cladding from the fiber to circumferences of 360° or 220°, as well as measured points along the length.

The most recent POF concept developed for medical use is a low cost, fused image type, which is available in 7,000 pixel counts, and in a wide range of .5mm to 2.5mm bundle diameters. POF image fiber is usable to three meters in length. It may be sterilized using the ETO Gas method. The resultant image fibers are highly flexible, while easily combined with POF for illumination purposes.

Consequently, a number of viable medical use devices may be developed for high reliability functions. Finally, with cost differences between glass and plastic image fibers so large, use of POF makes it ideal for economic disposability.

This article was written by Kenneth E. Eben, Marketing & Sales Director, Mitsubishi International Corp., New York, NY. For more information, visit http://info.hotims.com/45609-166.