Photonic semiconductors have become indispensable to modern defense — prized for their ultra-high-speed data processing, high capacity, low power consumption, and exceptional reliability. Yet despite their growing strategic importance, South Korea remains almost entirely dependent on foreign suppliers for these critical components. Industry leaders are now sounding the alarm: as global supply chains fracture along geopolitical lines, photonic semiconductors are no longer just industrial goods — they are national security assets, and South Korea’s access to them is far from guaranteed.