Fabrication of photonic devices directly written within glass using a femtosecond laser

Optical micrograph of waveguides written inside fused silica glass using a 300-500 nJ, 1 kHz, and 100 fs pulse train focused with a 0.42 NA microscope objective

Schematic diagram of U-grooved optical splitter.

Microscope image of U-groove machined by femtosecond laser pulses; (a) top view (×500), (b) side view (×500).

a b

Optical memoryFiber aligned one-input and two-output channels of U-grooved

optical splitter

Far-field pattern of the optical splitter’s output with a 1550 nm laser beam coupled into the input waveguide

The splitting ratio is approximately 1:1

Ik-Bu Sohn, Man-Seop Lee; Information and Communication University119, Munjiro, Yuseong-gu, Daejeon, 305-714, Korea

Optical microscope image of 3-D dot patterns consisted of three layers, which isapplicable to optical memory

b ca(a) I, (b) C, and (c) U,

respectively. The layer gap and dot pitch are 7 µm and

2 µm, respectively.

Microscope image of a 2-µm period (a) line and (b) dot patterns directly written insidefused silica with 320 nJ pulse energy

Line width and dot diameter are 0.5 µmba