Bipolar components (diodes, transistors, thyristors) are essential for very high-voltage power electronics. Recently, an optical high-voltage 4H-SiC BJT (Bipolar Junction Transistor) has been designed, fabricated and characterized. The BJTs were fabricated on a 4H-SiC wafer using a 120 μm thick epilayer with a doping concentration of 8×1014 cm−3 [1] and were designed to withstand a voltage of 10 kV. After electrical characterization, a breakdown voltage of about 11 kV was obtained [2]. PiN diodes have been integrated in the mask layout as part of this project to optically trigger high-voltage bipolar components (Fig. 1, right). In order to verify the effectiveness of their peripheral protection, different geometries were considered: MESA only, MESA combined with JTE, with and without supplementary 6 JTE rings, with round and square shapes.These diodes have been characterized in a vacuum chamber up to a reverse voltage of 1000 V and exhibita low leakage current as shown in Fig. 1, a prerequisite for OBIC characterization measurements in reverse.This paper aims to demonstrate how the micro-OBIC technique [3] can be used to assess the efficiency of peripheral protection by analyzing the 2D distribution map of the currents within the device structure, particularly at the junction periphery.2 types of circular diodes were chosen for illustration: a MESA diode and a MESA diode with JTE and 6 rings. Micro-OBIC measurements were carried out in air, limiting the reverse voltage applied to avoid breakdown. The OBIC 2D-maps are shown in Fig. 2, where the junction is clearly evidenced. At the same time, finite element simulations were carried out with SentaurusTM [4] in transient mode, taking into account the diode structure (Fig. 3) and the characteristics of the laser optical beam. Simulations of this kind are rare [5] and time-consuming. Fig. 4 shows currents as a function of diode diameter for the diode protected with the MESA. As it can be observed, both the experimental and simulated OBIC behavior are almost identical: the optically induced current increases and widens at the junction if the reverse voltage increases.