OPN April 2008

Cover Story

Testing Aspheres

Christof Pruss, Eugenio Garbusi and Wolfgang Osten

Optical designers are working to develop approaches for aspheric metrology that combine accuracy with flexibility. This article addresses current developments and reviews the state of the art in testing with computer-generated... more>>


Optical Signal Processing Based on All-Optical Analog-to-Digital Conversion

Akihiro Maruta and Sho-ichiro Oda

The nonlinearity of optical fiber provides attractive functionalities for all-optical signal processing. Recently, researchers have extensively studied all-optical analog-to-digital and digital-to-analog converters in an effort to surpass the inherently limited operating speed of these devices’ electronic counterparts. more>>

Retinal Transplants: Hope to Preserve and Restore Vision

Magdalene J. Seiler, Robert B. Aramant and Hans Keirstead

Transplantation of retinal progenitor cell layers may be a viable treatment for devastating eye diseases such as retinitis pigmentosa and macular degeneration. In several studies of animals with retinal degeneration, transplants of intact sheets of immature retinal cells improved vision—a finding that was validated in recent clinical research in humans. However, data from more patients are needed to confirm this as a valid therapy. more>>


Bionic Eyes for Daily Wear?

Yvonne Carts-Powell

Researchers at the University of Washington are developing the first steps to building a heads-up display in a contact lens. more>>

A Teeny, Tiny Spectrometer

Yvonne Carts-Powell

Graduate student Benjamin Lee of Harvard University and his colleagues recently demonstrated a light source that provides a broad range of wavelengths. more>>

Did You Know?

Yvonne Carts-Powell

Hollow-core photonic bandgap fibers. more>>



Active Learning in Optics and Photonics

Minella C. Alarcon

Improving optics education is not just about getting students to learn better; it is also about encouraging teachers to teach better. That is what UNESCO’s Active Learning in Optics and Photonics (ALOP) project is all about. more>>

Optical Engineering

Spare the Rod: Using Laser Trackers to Build Optical Test Systems

Brian Hart

The optical engineer is always on the lookout for new metrology techniques and equipment for optical alignment, particularly in light of the increasing demand for high-performance systems. A recent addition to the alignment toolbox is the laser tracker, a remarkably flexible metrology device. more>>

Optics Innovations

Court-Based Patent Reform

Joseph E. Gortych

Congress is considering making well-publicized reforms that would overhaul the U.S. patent system. However, the Supreme Court and the Court of Appeals for the Federal Circuit (CAFC) have already begun substantially changing the rules of the patent game. more>>

The History of OSA

Membership Directories and JOSA Indexing

John N. Howard

As OSA grew from a small group of opticians into a thriving society, how did it manage to keep track of all its members and journal articles? Lists, lists and more lists. more>>

Conversations in Optics

OPN Talks with Ian Walmsley

Colleen Morrison

Our conversation with Ian Walmsley, expert on quantum phenomena and CLEO/QELS speaker. more>>