Shanghai Securities research report pointed out that the upstream raw material supply is tight, focusing on investment opportunities in optical modules. The production and delivery period of optical chips and electric chips are relatively long, and additional orders of optical modules may cause upstream raw material supply capacity shortages. On the one hand, the imbalance of supply and demand in the upstream raw material market may lead to the formation of a seller's market. Optical module manufacturers with upstream supplier resources are expected to increase profit margins by raising prices; on the other hand, as the yield of silicon optical modules gradually improves, cost advantages will gradually emerge. Recommendations: 1) Optical module: Zhongji Innolight, Suzhou TFC Optical Communication, etc.; 2) Optical chip: Source Photonics, Accelink Technologies, etc.; 3) Switch: Unisplendour Corporation, etc.