KDP CONV
Grade · default condition
CONV = 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.
Values for the CONV 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 |
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 |
CONVDefaultThis page 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 CONV?
KDP CONV is KDP in the CONV grade — default choice for Pockels cells, SHG/THG plates and small-to-medium apertures where highest optical homogeneity and damage threshold matter. KDP CONV has a tensile strength of 12 MPa (1.74 ksi), weaker than 92% of glass grades. Elongation at break is 0% and the elastic modulus is 44 GPa (6.38 Msi). KDP CONV has a density of 2.34 g/cm³ (0.0845 lb/in³), lighter than 80% of glass grades. It melts at 253°C (487 °F).
Advantages
- Lightweight — 2.34 g/cm³ (0.0845 lb/in³), better than 80% of glass grades
Limitations
- Limited service temperature — 80°C (176 °F), worse than 100% of glass grades
- Low fracture toughness — 0.15 MPa·√m (0.137 ksi·√in), worse than 97% of glass grades
- Needs corrosion protection — 8/100, worse than 94% of glass grades
- Low stiffness — 44 GPa (6.38 Msi), worse than 83% of glass grades
KDP CONV properties
Typical room-temperature values for KDP CONV; 16 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 CONV has a density of 2.34 g/cm³ (0.0845 lb/in³), lighter than 80% of glass grades. It melts at 253°C (487 °F).
Mechanical13
KDP CONV has a tensile strength of 12 MPa (1.74 ksi), weaker than 92% of glass grades. Elongation at break is 0% and the elastic modulus is 44 GPa (6.38 Msi).
Thermal5
KDP CONV is rated for continuous service to 80°C (176 °F). It conducts heat at 1.3 W/m·K (0.751 BTU/hr·ft·°F), worse than 53% of glass grades. Thermal expansion is 33 µm/m·K (18.3 µin/in·°F).
Electrical5
KDP CONV is an electrical insulator with a dielectric strength of 20 kV/mm (508 V/mil) and a resistivity of 1×10⁸ Ω·m.
Chemical & Environmental2
Corrosion resistance is not recommended (8/100), worse than 94% of glass grades.
Manufacturability2
KDP CONV's machinability is poor (30/100, better than 71% of glass grades).
Common Calculations4
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with KDP CONV
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 CONV — frequently asked
What is KDP CONV used for?
KDP CONV 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 CONV?
KDP CONV has a typical tensile strength of 12 MPa (1.74 ksi) — weaker than 92% of glass grades. Strength varies by condition: see the 3 listed tempers.
Is KDP CONV 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 CONV 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 CONV?
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 CONV 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 CONV?
KDP CONV 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.