Highly reliable 1060nm metal aperture single-mode VCSEL with 180Gbps direct modulation at 85°C

Vertical-cavity surface emitting lasers (VCSELs) offer inherent advantages such as low power consumption and highspeed direct modulation thanks to their ultra-compact cavity. In this paper, we demonstrate 1060nm metal-aperture single-mode (MA-SM) VCSELs featuring high-speed direct modulation and high reliability, highlighting their excellent electrostatic discharge (ESD) tolerance and robust performance in accelerated aging test, even with a reduced oxide aperture. The top distributed Bragg reflector (DBR) of the 1060nm MA-SM VCSEL consists of a semiconductor DBR and a dielectric DBR to form the electrode near the cavity region for transverse coupled cavity (TCC) implementation. The stable single-mode lasing is achieved even with an oxide aperture diameter of 5µm thanks to the TCC effect. The -3dBo small signal bandwidth is 33GHz at 25°C and 30GHz at 85°C, respectively. The PAM4 operation up to 180Gbps for back-to-back transmission was also demonstrated. The transmitter dispersion and eye closure quaternary (TDECQ) at 160Gbps is 1.8dB at 25°C and 3.7dB at 85°C, while for 180Gbps it is 3.6dB at 25°C and 5.5dB at 85°C, respectively. In addition, the ESD tolerance and the accelerated aging tests were conducted. The 1060nm MA-SM VCSELs exhibit superior ESD tolerance compared to 850nm multi-mode VCSELs with the same oxide aperture. In accelerated aging test until 600 hours, no failures are observed for the 1060nm MA-SM VCSELs, indicating that the lifetime exceeds 10 years under conditions of 85°C and 7.5mA.