Encyclopedia … combined with a great Buyer's Guide!

Solid-state Lasers

Acronym: SSL

Definition: lasers based on solid-state gain media (usually ion-doped crystals or glasses)

More general term: lasers

More specific terms: doped insulator lasers, all-solid-state lasers, bulk lasers, fiber lasers, semiconductor lasers

German: Festkörperlaser

Category: laser devices and laser physicslaser devices and laser physics


Cite the article using its DOI: https://doi.org/10.61835/qcw

Get citation code: Endnote (RIS) BibTex plain textHTML

Solid-state lasers are lasers based on solid-state gain media such as crystals or glasses doped with rare earth or transition metal ions. Semiconductor lasers are also solid-state lasers, but they are not always meant with that term.

Ion-doped solid-state lasers (also sometimes called doped insulator lasers) can be made in the form of bulk lasers, fiber lasers, or other types of waveguide lasers.

Solid-state lasers may generate output powers between a few milliwatts and (in high-power versions) many kilowatts.

The first solid-state laser – and in fact the first of all lasers – was a pulsed ruby laser, demonstrated by Maiman in 1960 [1]. Later on, however, other solid-state gain media were preferred because of their superior performance. A major problem with ruby is its pronounced three-level nature.

Optical Pumping

Many solid-state lasers are optically pumped with flash lamps or arc lamps. Such pump sources are relatively cheap and can provide very high powers. However, they lead to a fairly low power efficiency, moderate lifetime, and strong thermal effects such as thermal lensing in the gain medium.

Laser diodes are now most often used for pumping solid-state lasers. Such diode-pumped solid-state lasers (DPSS lasers, also called all-solid-state lasers) have many advantages, in particular a compact setup, long lifetime, and often very good beam quality.

Energy Storage

The laser transitions of rare-earth or transition-metal-doped crystals or glasses are normally weakly allowed transitions, i.e., transitions with very low oscillator strength, which leads to long upper-state lifetimes and consequently to good energy storage, with upper-state lifetimes of microseconds to milliseconds. For example, a laser crystal pumped with 10 W of power and having an upper-state lifetime of 1 ms can store an energy of the order of 10 mJ.

end-pumped laser
side-pumped laser
Figure 1: Typical setups of solid-state bulk lasers, converting pump light (blue) into laser light (red): end-pumped (top) and side-pumped (bottom) versions.

Although energy storage is beneficial for nanosecond pulse generation (see below), it can also lead to unwanted spiking phenomena in continuous-wave lasers, e.g. when the pump source is switched on.

Pulse Generation

The long upper-state lifetimes makes solid-state lasers very suitable for Q switching: the laser crystal can easily store an amount of energy which, when released in the form of a nanosecond light pulse, leads to a peak power which is orders of magnitude above the achievable average power. Bulk lasers can thus easily achieve millijoule pulse energies and megawatt peak powers.

In mode-locked operation, solid-state lasers can generate ultrashort pulses with durations measured in picoseconds or femtoseconds (minimum: ≈ 5 fs, achieved with Ti:sapphire lasers). Some passively mode-locked solid-state lasers have a tendency for Q-switching instabilities, but these can usually be suppressed with suitable measures.

Wavelength Tuning

In terms of their potential for wavelength tuning, different types of solid-state lasers differ considerably. Most rare-earth-doped laser crystals, such as Nd:YAG and Nd:YVO4, have a fairly small gain bandwidth of the order of 1 nm or less, so that tuning is possible only within a rather limited range. On the other hand, tuning ranges of tens of nanometers and more are possible with rare-earth-doped glasses, and particularly with transition-metal-doped crystals such as Ti:sapphire, Cr:LiSAF and Cr:ZnSe (→ vibronic lasers).

Typical Solid-state Lasers

Examples of different types of solid-state lasers are:

More to Learn

Encyclopedia articles:


The RP Photonics Buyer's Guide contains 137 suppliers for solid-state lasers. Among them:


[1]T. H. Maiman, “Stimulated optical radiation in ruby”, Nature 187, 493 (1960) (first experimental demonstration of a laser); https://doi.org/10.1038/187493a0
[2]R. L. Byer, “Diode laser-pumped solid-state lasers”, Science 239, 742 (1988); https://doi.org/10.1126/science.239.4841.742
[3]G. Huber, C. Kränkel, and K. Petermann, “Solid-state lasers: status and future”, J. Opt. Soc. Am. B 27 (11), B93 (2010); https://doi.org/10.1364/JOSAB.27.000B93
[4]D. C. Hanna and W. A. Clarkson, “A review of diode-pumped lasers”, in Advances in Lasers and Applications (eds. D. M. Finlayson and B. Sinclair), pp. 1–18, Taylor & Francis, New York(1999)
[5]W. Koechner, Solid-State Laser Engineering, 6th edn., Springer, Berlin (2006)
[6]A. Sennaroglu (ed.), Solid-State Lasers and Applications, CRC Press, Boca Raton, FL (2007)
[7]R. Paschotta, Field Guide to Lasers, SPIE Press, Bellingham, WA (2007)
[8]R. Paschotta, “Operation regimes of solid-state lasers”, chapter in Handbook of solid-state lasers: Materials, systems and applications, editors: B. Denker, and E. Shklovsky, Woodhead Publishing (2013), ISBN 0 85709 272 3

(Suggest additional literature!)

Questions and Comments from Users


Could you please explain why most solid state laser can generate pulses shorter than the average lifetime of the excited state.

The author's answer:

The upper-state lifetime is not relevant because it is the lifetime in the absence of light. With a short intense pulse, you can extract the stored energy within a much shorter time.


In some real solid-state continuous-wave lasers it is possible to observe mode hopping. What is the reason of that?

The author's answer:

See the article on mode hopping.

Here you can submit questions and comments. As far as they get accepted by the author, they will appear above this paragraph together with the author’s answer. The author will decide on acceptance based on certain criteria. Essentially, the issue must be of sufficiently broad interest.

Please do not enter personal data here. (See also our privacy declaration.) If you wish to receive personal feedback or consultancy from the author, please contact him, e.g. via e-mail.

Spam check:

By submitting the information, you give your consent to the potential publication of your inputs on our website according to our rules. (If you later retract your consent, we will delete those inputs.) As your inputs are first reviewed by the author, they may be published with some delay.


Share this with your network:

Follow our specific LinkedIn pages for more insights and updates: