Gas phase evaporation device for preparing rare earth doped preform

The invention discloses a gas phase evaporation device for preparing a rare earth doped preform. The gas phase evaporation device comprises an ultra-clean chamber, a material tank chamber, a valve heat preservation chamber and a high-temperature steam conveying device. The raw materials are filled into the material tank through the ultra-clean chamber, so that pollution and deliquescence caused by contact between the raw materials and the atmosphere are avoided; the high-temperature steam conveying device located in the heat preservation cavity is adopted, the system is simple and reliable, the raw materials can be made to be at a constant temperature, and the stability of the system is improved. The system and the device have the advantages of being ultra-clean, compact in structure, good in heat preservation effect, convenient to operate, good in air tightness, low in energy consumption, low in cost and long in service life. The rare earth and co-doping agent raw materials can be ensured to be in an ultra-c