Nd:YAG

Precursor Preparation

High-purity Y₂O₃, Al₂O₃, and Nd₂O₃ powders are weighed in the required stoichiometric ratio and mixed thoroughly. The Nd³⁺ dopant level is selected based on the required optical performance.

Molybdenum Crucible Loading

The prepared oxide charge is loaded into a molybdenum crucible. The crucible material must withstand the high growth temperature and remain compatible with the furnace atmosphere and process conditions.

High-Temperature Melting

The charge is heated to the melting temperature of Nd:YAG inside the growth furnace. The melting process is carried out under a controlled protective atmosphere to limit crucible oxidation and maintain stable growth conditions.

Seed Crystal Introduction

A properly oriented YAG seed crystal is slowly lowered toward the melt surface. Careful contact is required to avoid thermal shock and seed cracking.

Necking and Shoulder Formation

A small neck may be formed first to improve crystal quality, followed by gradual widening of the crystal to the target diameter. This stage helps establish stable single-crystal growth.

Body Growth

The crystal is pulled slowly under controlled temperature and rotation conditions to maintain diameter uniformity and good optical quality. Stable thermal conditions are important for uniform dopant distribution and low defect formation.

Tailing, Cooling, and Harvest

At the end of growth, the crystal is tapered and separated from the melt. The boule is then cooled carefully to reduce thermal stress and prevent cracking.

Post-Growth Processing

The grown boule is cut, ground, lapped, and polished according to the required laser rod or optical component dimensions. Additional finishing and coating steps are carried out depending on the final application.