The ICARUS T600 LAr TPC is the far detector of the Short Baseline Program at FNAL. As it will have to work at shallow depth in the Booster Neutrino Beam, a large cosmic rays background (~ 11 kHz) will be present. To reduce it, precise timing information is needed from the new light detection system, based on 360 large area photomultipliers. For precise time measurements a calibration system based on a fast laser diode and a system based on one optical switch, several 01 × 1 fused fiber splitters, ultra-high vacuum optical feedthroughs and multimode optical patchcords up to 20 m long, to distribute the laser pulses to each single PMT, was designed. The time evolution of the PMTs' gain/timing and possibly their initial calibrations at a time t0 will be done by using this system. The expected time resolution of this calibration system will be around 100 ps. The laboratory tests needed to set up the system are reported.

中文翻译：

---

FNAL 的 ICARUS T600 探测器的激光二极管校准系统

ICARUS T600 LAr TPC 是 FNAL 短基线计划的远探测器。由于它必须在助推器中微子束的较浅深度处工作，因此将存在大的宇宙射线背景（~ 11 kHz）。为了减少它，新的光检测系统需要精确的时间信息，基于 360 个大面积光电倍增管。对于精确的时间测量，一个基于快速激光二极管的校准系统和一个基于一个光开关的系统、几个 01 × 1 熔融光纤分路器、超高真空光学馈通和长达 20 m 的多模光学跳线，以分配激光脉冲到每个单个 PMT，被设计。PMT 增益/定时的时间演变以及它们在时间 t0 可能的初始校准将通过使用该系统来完成。该校准系统的预期时间分辨率约为 100 ps。报告了设置系统所需的实验室测试。