Comparative analysis of optical gating time characterization methods for ultrafast gated image intensifiers with sub-nanosecond temporal resolution

Abstract

Ultrafast gated image intensifiers are crucial for capturing high-resolution images with sub-nanosecond temporal resolution. This study compares two methods for characterizing optical gating time in these intensifiers: Method I, involving a “laser pulse walkthrough,” and Method II, utilizing a fiber optic delay array. Both methods were applied to the same intensifier, with results analyzed for consistency and discrepancies. The findings indicate that both methods yield consistent optical gating times within their standard deviations range, though Method II exhibited greater dispersion at the photocathode edges due to spatial non-uniformity. The study further reveals that while the optical gating time distribution across the photocathode is uniformly consistent, a constant delay exists between different regions. To enhance measurement precision it is recommended to subdivide the photocathode for individual calibration of gating time and delay. These insights are pivotal for improving the precision and reliability of optical gating time measurements in applications requiring sub-nanosecond or even picosecond temporal resolution.