part of the Virtual Library
Here you get to the home page of the encyclopedia, giving you an overview on this resource.
Here, you can use the full-text search function for the whole RP Photonics website.
The Photonics Spotlight regularly presents high-quality information on technical and scientific aspects of photonics. Get it as a newsletter!
The RP Photonics Buyer's Guide is the ideal place for finding suppliers for photonics products.
Here you can browse encyclopedia articles grouped by topical categories.
The glossary summarizes the definition of terms from the enyclopedia articles.
Test yourself by solving a set of questions concerning laser technology, optical fibers, and nonlinear optics!
The immensely popular encyclopedia and buyer's guide make this website ideal for advertising photonics products.
Here you can search for articles where the title begins with a certain letter.
Here you can search for articles where the title contains a certain keyword.
See also the full text search which you find with the menu item "Search".
The small-signal gain of a
gain medium (e.g. a laser medium in a laser or amplifier) is the gain obtained for an input signal which is so weak that it does not cause any gain saturation.
In continuous-wave operation, this means that everywhere in the gain medium the signal intensity is well below the saturation intensity.
four-level laser gain medium with negligible ASE and no parasitic lasing, the small-signal gain in the steady state, as measured in decibels, is usually proportional to the absorbed pump power and to the stored energy.
The threshold of a laser or an optical parametric oscillator is reached when the small-signal gain equals the total resonator losses.
In a Q-switched laser, a high small-signal gain helps to achieve a short pulse duration.
In a high-gain amplifier (e.g. a fiber amplifier), the small-signal gain achievable is often limited by amplified spontaneous emission (ASE) or by parasitic lasing.
gain, laser threshold, threshold pump power and other articles in the categories optical amplifiers, physical foundations
If you like this article, share it with your friends and colleagues, e.g. via social media: