In the lasers and electro-optics industry many kinds of processes happen inside chambers. Most of them occur at the atomic or molecular level and aren’t visible with the naked eye in the traditional sense of "watching through the window." Examples of these invisible processes include deposition of optical coatings on different sizes and shapes of substrates and the metal-organic chemical-vapor deposition (MOCVD) growth of optoelectronic devices such as diode lasers, LEDs, and semiconductor detectors.
Optical coatings perform important functions, especially in high-energy laser applications. Ultraviolet-emitting excimer lasers are being increasingly applied in real-world processes. Laser manufacturers demand robust coatings on the numerous optics inside excimer lasers, and vendors have worked hard to meet these specifications. The view in the chamber in the cover photo shows finished excimer laser optics.
Detectors capture the image
Charge-coupled devices (CCDs) are often covered with antireflection coatings before being packaged. These chips are then assembled in cameras for machine-vision uses or in detector housings for instruments. The coatings on them are designed to improve performance or increase robustness. In some imaging applications, CCD cameras are used to monitor processes, but not at the molecular level. Used in conjunction with microscopes, CCD cameras reveal detailed structural information. They can distinguish objects on production lines, capture signals in spectroscopic instrumentation, or monitor activities over an area. Contributing editor Diana Zankowsky explains how to choose between various CCD cameras available in this month’s Product Focus article (see p. 137).
Once detectors are made—no matter from what material—their response must be calibrated for many applications. The steps in this process are important to ensure accuracy (see p. 129). Fiberoptic sensors use light delivered over optical fiber to detect information about displacement, strain, position, and other conditions. These sensors represent another application that is enjoying wider success as the appropriate technology matures. In this month’s Back to Basics, contributing editor Eric Lerner describes how fiberoptic sensors work and what developers hope to "see" with them (see p. 107). All in all, this issue of Laser Focus World serves as a window for viewing a number of applications of lasers and electro-optics.