CPO testing is splitting into four stages, with different suppliers positioned at each: · Stage 1: PIC and EIC wafer sort to identify known-good dies. Vendors: Keysight, Teradyne, Advantest and TEL · Stage 2: Integrated-wafer electro-optical testing after dicing, thinning and placement. Vendors: Keysight, Anritsu, MPI, Advantest, ficonTEC and Teradyne · Stage 3: Optical-engine testing combining electrical, optical and thermal testing. Vendors: ADST, All Ring, GMT Global, ficonTEC and Chroma ATE · Stage 4: Final CPO module testing across electrical, optical, thermal and reliability performance. Vendors: Hon Precision, Chroma ATE, Teradyne and WinWay Integrated electro-optical testing is a key bottleneck. It must test electrical and optical performance simultaneously while handling alignment, warpage and thermal expansion The opportunity extends beyond ATE. CPO also needs probing, lasers, fiber coupling, optical inspection, precision alignment, thermal control and automation