KEYWORDS: Optical fibers, Light emitting diodes, Optical microscopy, Photonic crystals, Near field scanning optical microscopy, Near field, Sapphire, Analytical research, Near field optics, Blue light emitting diodes
In our study, the distribution of the near-field close to the chip surface of Photonic Crystal (PhC)-patterned GaN-based
blue LED is measured with Near-field Scanning Optical Microscopy (NSOM). The blue LED has the layer structure
consisted of Sapphire substrate - n-GaN - Multi Quantum Well (MQW) - p-GaN - ITO, where the PhC pattern is
incorporated onto the top p-GaN layer. When the current is applied to the MQW, the light is emitted out of LED and the
near-field on the surface of LED chip is picked up by the fiber probe of NSOM system. The system was made by
ourselves, and the distance between the probe and the surface is controlled by shear force feedback control method using
tuning fork, where lock-in amplifier was used for noise reduction and for dithering the probe.
We propose the new concept of an optical triplexer for an application of Gigabit Ethernet Passive Optical Network (GEPON)
to Fiber-To-The-Home (FTTH) network. Based on a photonic crystal structure with local point defects, the optical
triplexer is optimally designed. The proposed device is analyzed by the plane wave expansion method and its
performance characteristics are evaluated by the finite-difference time-domain method. The optical triplexer proposed
here is designed to have a compact size of about 4 × 3 μm2 and the extinction ratios of -32.33 dB for 1310 nm, -19.84 dB for 1490 nm and -29.93 dB for 1550 nm, respectively.
In this paper, we newly propose an optical triplexer which is one of key components in Gigabit Ethernet Passive Optical
Network for Fiber-To-The-Home network. Based on a photonic crystal structure with local point defects, two types of
optical triplexers were optimally designed. The size-tuned optical triplexer shows the extinction ratios of -17.8 dB, -14.4
dB, and -15.9 dB for the wavelengths of 1310nm, 1490nm, and 1550 nm, respectively. And the index-tuned optical
triplexer shows the extinction ratios of -19.24dB, -17.09dB, and -22.68dB for the wavelengths of 1310nm, 1490nm, and
1550 nm, respectively. The size of the proposed optical triplexers were about 4 × 3 μm2.