Sungsub Kim

PQR laser can outdo LED

The PQR laser with ultra-low threshold current and sharp discrete multi-mode properties outdo conventional LEDs. We have fabricated 16times16 mesa type red PQR laser arrays at lambda = 610 nm and confirmed the superiority in luminous efficiency of PQR arrays to the conventional LEDs. We also present blue PQR laser arrays from GaN structures, which are very promising for display applications as well as low power high efficiency solid state lighting.

Two-dimensional soft output Viterbi algorithm with dual equalizers for bit-patterned media

This paper proposes a two-dimensional detection method using dual equalizers for bit-patterned media storage. The proposed method has improved bit error rate performance with low computational complexity.

Two-dimensional partial response maximum likelihood at rear for bit-patterned media

Compared with conventional partial response maximum likelihood (PRML), we propose new structure of two-dimensional (2D) PRML for bit-patterned media storage. The proposed PRML at rear shows superior bit error rate performance despite no iteration in 2D soft output Viterbi algorithm.

Focusing X-ray free-electron laser pulses using Kirkpatrick–Baez mirrors at the NCI hutch of the PAL-XFEL

Microfocusing of hard X-ray free-electron laser pulses using Kirkpatrick–Baez mirrors at the nano-crystallography and coherent imaging hutch of the Pohang Accelerator Laboratory X-ray Free-Electron Laser facility is reported.

Dense low threshold PQR lasers can outdo LEDs (Blue Quest)

PQR lasers with ultra-low threshold current and sharp discrete multi-mode properties can outdo conventional LEDs. We have confirmed many advantages of low injection, high efficiency, high frequency PQR arrays over the conventional LEDs. We also present blue PQR laser arrays from GaN structures, which are promising for display applications as well as high efficiency solid state lighting.