LETTERS
When two heads are better than one!
TopoMetrix was honored to receive a 1995 Laser Focus World Commercial Technology Achievement Award in the Instrumentation category for our Aurora near-field scanning optical microscope (NSOM). However, I would like to point out an error in the description of potential applications of the instrument that appeared in the January 1995 issue of Laser Focus World.
It was described that by pressing the surface, useful information would be gained. Also attaching antibodies to the probe was mentioned as a means for biochemical applications. Both of these types of probe manipulations are potentially useful techniques when using an atomic force microscope (AFM), which is another of our products. However, we would like to clarify, in order that the reader would not be confused about the applications of NSOM, that the NSOM ti¥cannot touch the surface, and compliance techniques are not practiced with the Aurora NSOM. To do both NSOM and AFM requires separate scanning heads. Both heads use the same electronics and software. The fact that the NSOM provides topographic and optical information of a sample was correctly described.
Thank you for allowing us to clarify this potential confusion about NSOM operations and for making us the proud recipients of one of your awards.
John A. Abbis
Senior Vice President
Marketing and Sales
TopoMetrix
5403 Betsy Ross Drive
Santa Clara, CA 95054-1162
Are they really eye-safe?
Re your article on lasers aiding law enforcement (Laser Focus World, Sept. 1994, p. 49)--I would like to make the following comments.
1. The use of the term "eye-safe laser" is inappropriate and incorrect. In the field of laser safety, this term is specifically used to denote lasers of wavelengths that do not penetrate ocular tissues.
2. The claimed safety of the proposed devices are based on an erroneous concept, that is, that the weapon will only be used against an assailant at a specified distance. A weapon that is an effective dazzle source at 1 km is a potential hazard at closer ranges.
3. Many police forces currently deploy high-intensity flashlamps. Even these are potentially hazardous at extremely close ranges.
4. Whilst I condone the underlying tenet of preserving life, the potential permanent blinding nature of these devices must be emphasized. These systems will be hazardous at short range.
I hope this information is helpful.
John Marshall
Guy`s and St. Thomas`s
Medical and Dental School
Department of Ophthalmology
St. Thomas`s Hospital
London SE1 7EH, UK
Bargain tables
Your article on optical table products (Laser Focus World, Jan. 1995, p. 103) was, as usual, a timely piece for our company. Choosing an optical table and supports is application-specific and in this day of tight and dwindling funds, cost is rapidly becoming a predominant factor. A new system can cost thousands of dollars. When there are other accessories to buy, a big-ticket item can seal the fate on stretched-to-the-limit capital.
Musser & Associates has an alternative to buying new. We offer renovated vibration-isolated table products to every budget-crunched individual who wants table systems for half the price.
Since we also purchase excess optical table products, we have provided an avenue for corporations to recapture some of the cost for projects that no longer exist.
MAI opened u¥in 1980, but expanded into the purchase and resale area just seventeen months ago. It`s very rewarding to know that our customers are able to get two systems for the price of one or obtain the system they really need rather than settling for the one that fits into the budget.
Sherryl Musser
Musser & Associates Inc.
Fountain Valley, CA 92708-3118
(714) 841-1002