Differences between Light-emitting diode (LED), Vertical-Cavity Surface-Emitting Laser (VCSEL) and Distributed Feedback (DFB) optical transmission
Unable to determine which optical transmission is better for signal integrity and single mode.
The I350-F2/F4 adapters are a good choice for only 1Gb . They are Short Reach (SR) only
The X710-DA4 or X710-DA2 adapters are a good choice for 1Gb or 10Gb. Transceivers are purchased separately and both Short Reach (SR) and Long Reach (LR) are available
LED is only suitable for speeds of up to 200Mb/s and they are not used for gigabit connections.
VCSEL is typically used for Short Reach (SR) Multimode connections at 1Gb/s, 10Gb/s, and 25Gb/s.
DFB lasers are more powerful and typically used for Long Reach (LR) single mode connections at 1Gb/s, 10Gb/s, and 25Gb/s.
Speeds greater than 25Gb/s are usually achieved by using multiple channels. For example, 40Gb/s is 4 channels of 10Gb each, requiring 8 fibers (4 for Transmit (TX) and 4 for Receive (RX)).