Time-Stretched Optical Frequency Comb Dispersive Fourier Transformation for Rapid Measurement of 3-D Morphology of Solar Cells

Accurate measurement and quality inspection of solar cell morphology are essential for ensuring high fabrication yield and device performance. Conventional techniques for online inspection are restricted by slow acquisition speed, limited resolution, or complex implementation, and thus cannot fully satisfy the demands of high-throughput manufacturing. To overcome these limitations, we propose a spectral interference measurement method based on an optical frequency comb (OFC) combined with time-stretched dispersive Fourier transform (TS-DFT), enabling real-time, continuous, and high-speed analysis. Theoretical analysis indicates that the minimum detection time per frame can reach 4 ns owing to the repetition rate of the OFC, whereas the practical acquisition speed in the current implementation is limited to the millisecond scale due to hardware constraints. Experimental results demonstrate a spectral resolution of 0.39 nm and high accuracy with root-mean-square errors of 0.543 μm (locked OFC) and 0.732 μm (unlocked OFC). These results confirm the capability of the proposed system for precise online inspection and its potential in 3D precision manufacturing.