Overview:
The realm of optical systems extends far beyond the traditional setup of a series of lenses and some sort of image sensor. For example, the addition of nonlinear optics can change the wavelength of light passing through the system, radically alter the properties of an image, or otherwise change light in ways that linear optics could never do. Active optics with movable elements can also change light in useful ways, enabling wavelength tuning and other alterations of a light beam’s properties. 

This e-digest focuses on the properties of innovative optical systems, with articles on:

• a nonlinear all-optical method to upconvert the wavelength of 2-D images
• an ultrafast nonlinear optical “time telescope” that squeezes more data into the same duration
• an active MEMS blazed grating that is tunable and very efficient

Of all ultrafast laser and amplifier gain media, the Ti:sapphire crystal is the most versatile. Not only does it have the broadest tuning range; it also can be scaled to very high pulse energies--accomplished by scaling up the crystal size. Both the technology itself and its uses are fascinating in their own right. This e-digest delves into a bit of both, with articles on:

• fabrication of the largest Ti:sapphire crystals
• a new laser especially designed for pumping Ti:sapphire
• a high-energy system using a Ti:sapphire-based CPA laser

Photodiodes are semiconductor-based light sensors. When illuminated, they generate a current or voltage proportional to the incident light intensity. There are several types of photodiodes, which are classified either by the semiconductor materials used or how they are constructed. These types include PN and PIN devices as well as Schottky type photodiodes and APDs (avalanche photodiodes).

Photodiodes are typically used for the detection of the intensity, position, color and presence of light. Some photodiodes have a very rapid response time, operating with bandwidths in the gigahertz range. Arrays of photodiodes can be used for imaging.

The laser is a premier tool for uses ranging from science to a huge range of industrial applications. And why? A laser beam is coherent and narrowband, and can be made very intense. But using this tool is dependent on knowing both the beam’s properties and how to tailor them. This e-digest provides three essential guides to:

• characterizing the beam profile of sophisticated lasers
• shaping the light from diode-laser arrays for best performance
• measuring sub-two-cycle femtosecond laser pulses

Overview: This unique collection of editorial articles were compiled together to provide you with a comprehensive perspective on PMTs. For decades, the PMT has been the premier choice for low-light detection.  Engineers and researchers continue to develop PMT technology, both to improve the device’s characteristics and to tailor its usefulness to the ever-increasing number of photonics applications being developed.  New photocathode materials, new dynode designs, and the advent of hybrid PMT/avalanche-diode structures are just some of the innovations that are expanding the PMT’s wavelength range, enabling multichannel outputs, and shortening response times.

The optics and photonics industry is feeling the global economic recession, like almost every other industry in the world. But technical advances in ultrafast lasers and optical filtering offer such extraordinary advances for applications in manufacturing and all types of research requiring visual inspection, it’s easy to be optimistic about the future. Read this editorial digest to get in-depth information from the experts in the industry on the state of the optoelectronics market, advancements in semiconductor processing and improvements in optical filters and what that offers.