  We present the design and test results of two optical data transmission ASICs
for the High-Luminosity LHC (HL-LHC) experiments. These ASICs include a
two-channel serializer (LOCs2) and a single-channel Vertical Cavity Surface
Emitting Laser (VCSEL) driver (LOCld1V2). Both ASICs are fabricated in a
commercial 0.25-um Silicon-on-Sapphire (SoS) CMOS technology and operate at a
data rate up to 8 Gbps per channel. The power consumption of LOCs2 and LOCld1V2
are 1.25 W and 0.27 W at 8-Gbps data rate, respectively. LOCld1V2 has been
verified meeting the radiation-tolerance requirements for HL-LHC experiments.
