Short address: rpp-con.com
Dr. Paschotta, the founder of RP Photonics, supports your R & D with his deep expertise. Save time and money with efficient support!
Short address: rpp-soft.com
Powerful simulation software for fiber lasers and amplifiers, resonator design, pulse propagation and multilayer coating design.
Short address: rpp-enc.com
The famous Encyclopedia of Laser Physics and Technology provides a wealth of high-quality scientific and technical information.
Short address: rpp-bg.com
In the RP Photonics Buyer's Guide, you easily find suppliers for photonics products. As a supplier, you can profit from enhanced entries!
Learn on lasers and photonics every day!
||part of the|
| | |
In the RP Photonics Buyer's Guide you can find plenty of suppliers for hundreds of photonics products.
Definition: an operation mode of lasers (e.g. diode bars) where the pump power is switched on for short time intervals in order to limit thermal effects
German: Quasi-CW-Betrieb, quasi-kontinuierlicher Betrieb
Quasi-continuous-wave (quasi-cw) operation of a laser means that its pump source is switched on only for certain time intervals, which are short enough to reduce thermal effects significantly, but still long enough that the laser process is close to its steady state, i.e. the laser is optically in the state of continuous-wave operation.
The duty cycle (percentage of “on” time) may be, e.g., a few percent, thus strongly reducing the heating and all the related thermal effects, such as thermal lensing and damage through overheating.
Therefore, quasi-cw operation allows the operation with higher output peak powers at the expense of a lower average power.
Pulsed operation with significantly shorter pumping times, where an optical steady state is not reached, is called gain switching.
Quasi-continuous-wave operation is most often used with diode bars and diode stacks.
Such devices are sometimes even designed specifically for quasi-cw operation: their cooling arrangement is designed for a smaller heat load, and the emitters can be more closely packed in order to obtain a higher brightness and beam quality.
Compared with ordinary continuous-wave operation, additional lifetime issues can result from quasi-cw operation, related e.g. to higher optical peak intensities or to frequent temperature changes.
Some doped-insulator solid-state lasers are also operated in quasi-cw operation.
Such lasers are sometimes called heat capacity lasers.
|||T. Dascalu et al., “100-W quasi-continuous-wave diode radially pumped microchip composite Yb:YAG laser”, Opt. Lett. 27 (20), 1791 (2002)|
|||C. Y. Li et al., “QCW diode-side-pumped Nd:YAG ceramic laser with 247 W output power at 1123 nm”, Appl. Phys. B 103 (2), 285 (2010)|
See also: continuous-wave operation, modes of laser operation, gain switching, diode bars, diode stacks
Categories: lasers, pulses
Have you seen the
RP Photonics Buyer's Guide?
It lists many hundreds of suppliers for photonics products, and is just one mouse click away from the extremely popular Encyclopedia of Laser Physics and Technology:
- In any product-related encyclopedia article, you find a box for the Buyer's Guide.
- Alternatively, click on the heading which your mouse pointer has just touched.
Our Buyer's Guide is what you need:
- easy handling, clear layout
- high-quality information
- additional technical information in the encyclopedia
And surely you will remember where to find this useful resource again!
Suppliers: get your free entries, and enhanced visibility with paid entries.
Resonator Design Software
RP Resonator – do you know a more flexible resonator design software?
Tailored Training Courses
Within one or two days, a tailored training course at your location can boost the competence of your team. An investment which can pay back very rapdily!
Read a random article every day in order to steadily learn about photonics!
RP Photonics Buyer's Guide
Do you know a better place to find suppliers for photonics items?
Search by product or by supplier.
Suppliers, show your products with free or enhanced entries!
Beam Propagation Software
Analyze beam propagation in specialty fibers, waveguides, couplers, etc. with the new version of RP Fiber Power!