Single-Channel 106.25 Gb/s PAM-4 and 64 Gb/s NRZ Transmission With a 33.4-GHz 850-nm VCSEL With low-RIN Characteristics

We report on a high-performance oxide-confined 850-nm vertical-cavity surface-emitting laser (VCSEL) believed to have the highest modulation bandwidth at low bias currents for datacenter applications. This article has extensively discussed the device's characteristics, including static performance, optical spectra, small-signal response, relative intensity noise (RIN), and large-signal performance. The VCSEL with an oxide aperture of 4 μm delivers a 3.7 mW optical power, low spectral width, below −150 dB/Hz VCSEL RIN, and a breakthrough 33.4 GHz frequency response at room temperature (25 °C). Designed for high-performance short-reach communication networks and telecommunication applications, this high-speed 850-nm VCSEL supports data rates of up to 64 Gb/s non-return-to-zero (NRZ) and 106.25 Gb/s (53.125 Gbaud) 4-level pulse amplitude modulation (PAM-4) in multi-mode fiber (MMF) without the need for feed-forward equalization (FFE), decision feedback equalizer (DFE), or any offline digital signal processing (DSP).