DKDP (Potassium Dideuterium Phosphate) is a nonlinear crystal that is commonly used in laser technology for frequency conversion. DKDP has a high nonlinear coefficient and a wide transparency range, making it a good material for second harmonic generation (SHG), sum frequency generation (SFG), and difference frequency generation (DFG).
In SHG, the frequency of a laser beam is doubled by passing it through a DKDP crystal. This process is used to generate light in the ultraviolet range, which is useful in applications such as fluorescence microscopy and laser spectroscopy.
SFG involves combining two laser beams of different wavelengths to create a new beam with a frequency equal to the sum of the input frequencies. DKDP is often used as the nonlinear crystal in SFG because of its high efficiency and low absorption. SFG is used in a range of applications, including in Raman spectroscopy and in the production of visible and ultraviolet light.
DFG produces a new frequency that is equal to the difference between two input frequencies. DKDP can be used in DFG to generate tunable infrared radiation, which has applications in spectroscopy, sensing, and imaging.
DKDP is also used in electro-optic modulators, which are devices that change the polarization of light in response to an electric field. DKDP has a high electro-optic coefficient, which makes it a good choice for these applications.
One advantage of DKDP is its relatively high damage threshold, which makes it suitable for high-power laser applications. However, DKDP is hygroscopic and can absorb moisture from the air, which can affect its performance. Careful handling and storage are required to maintain the crystal's quality.
|Transparency range, µm||0.2 - 2.1|
|Lattice parameters, Å||a=b=7.469; c=6.976|
|Refractive index at 407.8 nm :||no=1.5185; ne=1.4772|
|at 632.8 nm||no=1.5044; ne=1.4656 (at 623.4 nm)|
|at 1064 nm||no=1.4948; ne=1.4554|
|Non-linear coefficient at 1.064 µm, pm/V||d36 = 0.37|
|Optical damage threshold, MW/cm2||>100 (1064 nm, 20 ns)|