Hellma Calcium Fluoride (CaF ₂) LD-A Material with High Transmittance

Hellma Calcium Fluoride (CaF ₂) LD-A Material with High Transmittance

Core technical advantages of Hellma Calcium Fluoride LD-A model

193nm deep ultraviolet band dedicated optimization, ultra-high transmittance and low absorption loss

Hellma CaF ₂ LD-A material is a high-purity optical grade material developed specifically for the 193nm ArF excimer laser band, with optical transmission properties in the deep ultraviolet region. Conventional optical glass and quartz materials exhibit strong absorption and transmittance attenuation in the 193nm wavelength band, which cannot meet the requirements of laser transmission and photolithography imaging. On the other hand, LD-A type calcium fluoride single crystal has a transmittance of over 90% at 193nm and an extremely low absorption coefficient, with almost no laser energy loss or thermal accumulation. The material undergoes exclusive annealing in the ultraviolet band, impurity removal, and lattice optimization treatment to eliminate defects such as color centers, vacancies, and metal ions that cause ultraviolet absorption. This ensures that it does not fade, damage, or change its optical properties under continuous high-power ultraviolet laser irradiation. It is an ideal substrate for 193nm lithography systems, laser cleaning, and ultraviolet spectroscopy detection systems.

High quality single crystal structure and<111>excellent crystal orientation, optical uniformity industry

The product adopts single crystal (monokristalin) structure, and is composed of a single continuous lattice as a whole, without grain boundaries, dislocation aggregation, microcracks, and impurity segregation. Its optical uniformity is far superior to that of polycrystalline calcium fluoride and ordinary fused silica. Single crystal structure can ensure uniform refractive index, avoid scattering, distortion, and spot dispersion during light transmission, and ensure imaging accuracy and laser transmission quality.

At the same time, the product adopts a<111>crystal orientation, which has been extensively validated as an optimal orientation for calcium fluoride materials in deep ultraviolet laser applications. <111>The crystal plane has the highest structural symmetry, low birefringence, and excellent stress distribution characteristics, which can significantly reduce the sensitivity of laser-induced damage threshold (LIDT) and enhance the component's ability to resist high-power laser shock; Under high temperature, high pressure, and strong laser radiation environment, the<111>oriented lattice structure is more stable, without problems such as stress cracking, refractive index distortion, and increased birefringence, ensuring the long-term stable operation of the optical system.

Hellma Calcium Fluoride (CaF ₂) LD-A Material with High Transmittance