KDP DKDP-70
Grade
DKDP-70 = deuterated KD*P, ~70–98 % deuteration
Choose when low 1.06 µm absorption, larger electro-optic coefficient (lower half-wave voltage) or extended IR transmission to ~1.6 µm is required.
Values for the DKDP-70 condition
Other KDP tempers and conditions
KDP is listed in 3 conditions; see the grade overview at KDP.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Rapid-growth large-aperture KDP | Pick for metre-class ICF laser frequency-conversion and plasma-electrode Pockels-cell plates where aperture and lead time dominate over ultimate homogeneity. | — | 11 | 0 | 170 HV | 1 W/m·K |
DKDP-70This page Deuterated KD*P, ~70–98 % deuteration | Choose when low 1.06 µm absorption, larger electro-optic coefficient (lower half-wave voltage) or extended IR transmission to ~1.6 µm is required. | — | 11 | 0 | 165 HV | 1 W/m·K |
CONVDefault Conventional slow solution growth, laser/optical grade | Default choice for Pockels cells, SHG/THG plates and small-to-medium apertures where highest optical homogeneity and damage threshold matter. | — | 12 | 0 | 170 HV | 1 W/m·K |
What is KDP DKDP-70?
KDP DKDP-70 is KDP in the DKDP-70 grade — choose when low 1.06 µm absorption, larger electro-optic coefficient (lower half-wave voltage) or extended IR transmission to ~1.6 µm is required. KDP DKDP-70 has a tensile strength of 11 MPa (1.6 ksi), weaker than 92% of glass grades. Elongation at break is 0% and the elastic modulus is 42 GPa (6.09 Msi). KDP DKDP-70 has a density of 2.36 g/cm³ (0.0851 lb/in³), lighter than 78% of glass grades. It melts at 253°C (487 °F). CONV is the default condition FabDigit quotes; DKDP-70 is available on request or by drawing note.
Advantages
- Lightweight — 2.36 g/cm³ (0.0851 lb/in³), better than 78% of glass grades
Limitations
- Limited service temperature — 80°C (176 °F), worse than 100% of glass grades
- Low fracture toughness — 0.14 MPa·√m (0.127 ksi·√in), worse than 98% of glass grades
- Needs corrosion protection — 8/100, worse than 94% of glass grades
- Low stiffness — 42 GPa (6.09 Msi), worse than 83% of glass grades
KDP DKDP-70 properties
Typical room-temperature values for KDP DKDP-70; 18 are specific to this condition. Other listed values are KDP reference data and may not represent this condition. Bars are the position among glass grades.
Physical5
KDP DKDP-70 has a density of 2.36 g/cm³ (0.0851 lb/in³), lighter than 78% of glass grades. It melts at 253°C (487 °F).
Mechanical13
KDP DKDP-70 has a tensile strength of 11 MPa (1.6 ksi), weaker than 92% of glass grades. Elongation at break is 0% and the elastic modulus is 42 GPa (6.09 Msi).
Thermal5
KDP DKDP-70 is rated for continuous service to 80°C (176 °F). It conducts heat at 1.3 W/m·K (0.722 BTU/hr·ft·°F), worse than 54% of glass grades. Thermal expansion is 33 µm/m·K (18.3 µin/in·°F).
Electrical5
KDP DKDP-70 is an electrical insulator with a dielectric strength of 20 kV/mm (508 V/mil) and a resistivity of 5×10⁸ Ω·m.
Chemical & Environmental2
Corrosion resistance is not recommended (8/100), worse than 94% of glass grades.
Manufacturability2
KDP DKDP-70's machinability is poor (30/100, better than 71% of glass grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with KDP DKDP-70
Is KDP easy to machine?
Never use water — saw with wire/OD blade in oil or kerosene, then single-point diamond flycut; cleaves on {100}/{101}, so keep cuts light and stress-free.
Can KDP be welded?
Not weldable; elements are optically contacted, edge-bonded with low-stress adhesive, or mounted in oil-filled or dry-N2 hermetic cells.
Can KDP be formed, bent or molded?
Grown only from aqueous solution (temperature-lowering or rapid point-seed supersaturation) over weeks to months; no melt or ceramic forming route.
What surface finishes work on KDP?
Diamond flycut to λ/10 flatness and <2 nm rms, then sol-gel or low-temperature e-beam AR coating; store and use below ~40 % RH with desiccant.
KDP chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Kstoichiometric KH2PO4, M=136.09 g/mol | 28.6 – 28.8 | 28.73 |
| P | 22.6 – 22.9 | 22.76 |
| Hacidic protons; replaced by D in DKDP variant | 1.4 – 1.55 | 1.48 |
| metallic impurities (Fe, Cr, Al, Si)ppm-level control required for damage threshold | ≤ 0 | 5×10⁻⁴ |
| O | balance | — |
KDP DKDP-70 — frequently asked
What is KDP DKDP-70 used for?
KDP DKDP-70 is typically used for laser frequency doubling/tripling, pockels cell electro-optic switches and high-power laser systems (e.g., ICF). In short: largest-aperture NLO crystal; water-soluble, oil machining only; 80 °C service ceiling.
What is the tensile strength of KDP DKDP-70?
KDP DKDP-70 has a typical tensile strength of 11 MPa (1.6 ksi) — weaker than 92% of glass grades. Strength varies by condition: see the 3 listed tempers.
Is KDP DKDP-70 easy to machine?
Not especially — machinability is rated poor (30/100, better than 71% of glass grades). Never use water — saw with wire/OD blade in oil or kerosene, then single-point diamond flycut; cleaves on {100}/{101}, so keep cuts light and stress-free.
Can KDP DKDP-70 be welded?
Not weldable; elements are optically contacted, edge-bonded with low-stress adhesive, or mounted in oil-filled or dry-N2 hermetic cells.
What surface finishes work on KDP DKDP-70?
Diamond flycut to λ/10 flatness and <2 nm rms, then sol-gel or low-temperature e-beam AR coating; store and use below ~40 % RH with desiccant.
Can KDP DKDP-70 be formed, bent or molded?
Grown only from aqueous solution (temperature-lowering or rapid point-seed supersaturation) over weeks to months; no melt or ceramic forming route.
What is the maximum service temperature of KDP DKDP-70?
KDP DKDP-70 is rated for continuous use to about 80°C (176 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- Properties of Optical and Laser-Related Materials — Wiley (Marvin J. Weber) (1997)
- Nonlinear Optical Crystals: A Complete Survey — Springer (D. N. Nikogosyan) (2005)
- KDP / DKDP nonlinear and electro-optic crystal datasheets — CASTECH / EKSMA Optics / Fuzhou crystal suppliers (2024)
- Landolt-Börnstein: Elastic, Piezoelectric and Dielectric Constants of Crystals (KDP group) — Springer (1993)
- KDP/DKDP KH2PO4 (2025)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.