IdealPhotonics' 1625-1675nm DFB diode, based on an InGaAsP/InP strained superlattice and a subatomic-level Bragg grating (±0.0008nm accuracy) U-band laser, achieves a side-mode suppression ratio of >80dB and quantum-limited stability of ±0.0002nm/℃. In cutting-edge applications such as 1645nm special gas detection (0.005ppb sensitivity), 1650nm molecular fingerprinting, and 1675nm space laser communication, it simultaneously breaks through the 0.0003cm⁻¹ spectral resolution and 72Gbps PAM8 modulation limit. Its record-breaking 78% power conversion efficiency and ultra-limited noise characteristics of -168dB/Hz redefine the performance ceiling of ultra-long wavelength optoelectronic chips.Employing an InGaAsP/InP quantum well and a subpicometer-level Bragg grating (±0.0008nm accuracy), this device achieves a side-mode suppression ratio of >80dB and quantum-limited stability of ±0.0002nm/℃. It simultaneously breaks through spectral resolution of 0.0003cm⁻¹ and a PAM8 modulation rate of 72Gbps in three cutting-edge fields: 1645nm trace gas detection (0.005ppb sensitivity), 1650nm molecular fingerprint spectroscopy, and 1675nm deep space communication. Its 78% power conversion efficiency and -168dB/Hz ultra-limiting noise characteristics make this device the world's first revolutionary optoelectronic chip to combine "atomic-level spectral precision with terahertz communication fronthaul capabilities."