“…Between 1990 and 2010, a new effective technology for growing in protective reducing media based on CO and H 2 using carbon-containing constructional materials was developed, which significantly reduced the burnout of the thermal zone. , At present, leucosapphire crystals of record size up to ∼500 × 1000 × 50 mm 3 are obtained by the modified HDC method. , This technology is successfully used to grow Ti:Sa laser crystals too. Due to the reducing conditions of growth, an efficient transition of Ti 4+ → Ti 3+ ions occurs. − As a result, crystals with a concentration of up to 0.3–0.35 mass % Ti were obtained.…”