IdealPhotonics' MCT (Metal Cadmium Telluride) photodiode is an infrared detector based on an HgCdTe alloy with a tunable bandgap. By adjusting the cadmium composition, it achieves full infrared band coverage from 1 to 30 μm, reaching the photon-level detection limit at deep cooling (77 K), becoming the gold standard for high-precision military infrared and astronomical observations.Its precise tunability (1-30 μm) across the entire infrared band and extreme detection performance are achieved through composition gradient technology to achieve background-limited detection (BLIP). At a low temperature of 77 K, the dark current is as low as the electronic noise floor. However, this achievement relies on complex lattice matching processes and a high-cost cooling system.