In a slab (parallel flat plate), the input breakdown limit is proportional to the length and lateral width of the slab, and is inversely proportional to the thickness of the slab. Compared with a rod of the same length, the slab allows a larger breakdown limit input and has the possibility of making a larger output available. For slab excitation, use of fiber collected laser diodes as the optical pumping light source is proposed.

Laser diodes used for solid-state laser excitation are selected on the basis of required power and wavelengths. Many of the Sony laser diodes ranging from the 90mW SLD301 to 60W SLD433 can be used in a wide range of applications.
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Wavelength tuning procedure
There are cases where the laser diode emission wavelength is adjusted to a specific wavelength such as when used for excitation of solid-state lasers like YAG and YLF. In such a case, one of the features of laser diodes is a tuning method that utilizes the wavelength temperature characteristics.
Example) YAG excitation
• Absorption band of YAG: λ = 807nm
• Laser diode: SLD326YT-25
Specification: λ = 810 ± 3nm
(Tth = 25ºC: Thermistor temperature)
The actually supplied data is assumed to be λ = 810nm.
• Wavelength temperature coefficient: 0.3nm/ºC
For tuning to absorption band wavelength λ = 807nm;
 Δλ = 810nm - 807nm = 3nm
 ΔT = 3nm ÷ 0.3nm/ºC = 10ºC
Therefore, ΔT = 10ºC cooling must be done.
That is, the temperature must be lowered to;
 Tth = 25ºC – 10ºC = 15ºC
Therefore, adjust the current of the TE cooler so that the thermistor resistance RTH found from the graph of Fig. 10 will be;
 RTH = 15kΩ