This letter is the first experimental demonstration of layered/enhanced asymmetrically clipped optical single-carrier frequency-division multiplexing (L/E-ACO-SCFDM) in short-reach optical interconnects. An optimized method is employed to significantly improve the performance of L/E-ACO-SCFDM. L/E-ACO-SCFDM has higher spectral efficiency than ACO-SCFDM, and it also has lower peak-to-average power ratio and computational complexity than L/E-ACO orthogonal frequency-division multiplexing (L/E-ACO-OFDM). In the experimental system, the low-cost electrical and optical devices are utilized, which induce serious high-frequency distortion caused by bandwidth limitation. Under the same spectral efficiency and net bit rate, the optimized L/E-ACO-SCFDM has about 4-dB and more than 3-dB receive sensitivity improvement at 7% forward error correction limit compared with the optimized L/E-ACO-OFDM and the optimized ACO-SCFDM, respectively. Therefore, L/E-ACO-SCFDM is a promising scheme for the future short-reach optical interconnects.