Potassium Dihydrogen Phosphate (KDP) and Potassium Deuterium Phosphate (DKDP) are among the most widely-used commercial nonlinear optical (NLO) crystals, recognized for their exceptional frequency conversion and electro-optic properties. These crystals are extensively employed for second-, third-, and fourth-harmonic generation of Nd:YAG lasers at room temperature, making them indispensable in high-power laser systems.

In addition to their nonlinear optical efficiency, KDP and DKDP exhibit high electro-optic coefficients, which make them ideal for electro-optical modulators, Q-switches, and Pockels cells. Their robust UV transmission, high optical damage threshold, and strong birefringence enable reliable performance in demanding laser applications.

Manufactured to precise tolerances with excellent surface quality, these crystals support high-quality beam propagation and consistent phase-matching, ensuring optimal conversion efficiency. DKDP crystals, in particular, are tailored for high-energy laser systems, with a laser damage threshold of 1 GW/cm² at 1064 nm (10 ns, 10 Hz). Non-hygroscopic and durable, KDP and DKDP crystals provide reliable long-term performance in both laboratory and industrial laser applications.