Multiple streams of high definition television (HDTV) and improved home-working infrastructure are currently driving
forces for potential fiber to the home (FTTH) customers . There is an interest to reduce the cost and physical size of
the FTTH equipment. The current fabrication methods have reached a cost minimum. We have addressed the costchallenge
by developing 1310/(1490)/1550nm bidirectional diplexers, by monolithic seamless integration of lasers,
photodiodes and wavelength division multiplexing (WDM) couplers into one single InP-based device. A 250nm wide
optical gain profile covers the spectrum from 1310 to 1550nm and is the principal building block. The device fabrication
is basically based on the established configuration of using split-contacts on continuos waveguides. Optical and electrical
cross-talks are further addressed by using a Y-configuration to physically separate the components from each other and
avoid inline configurations such as when the incoming signal travels through the laser component or vice versa. By the
eliminated butt-joint interfaces which can reflect light between components or be a current leakage path and by leaving
optically absorbing (unpumped active) material to surround the components to absorb spontaneous emission and nonintentional
reflections the devices are optically and electrically isolated from each other. Ridge waveguides (RWG) form
the waveguides and which also maintain the absorbing material between them. The WDM functionality is designed for a
large optical bandwidth complying with the wide spectral range in FTTH applications and also reducing the polarization
dependence of the WDM-coupler. Lasing is achieved by forming facet-free, λ/4-shifted, DFB (distributed feedback
laser) lasers emitting directly into the waveguide. The photodiodes are waveguide photo-diodes (WGPD). Our seamless
technology is also able to array the single channel diplexers to 4 to 12 channel diplexer arrays with 250μm fiber port
waveguide spacing to comply with fiber optic ribbons. This is an important feature in central office applications were
small physical space is important.
The ability to dynamically control the properties of a photonic crystal by basing such a crystal on a media exhibiting electromagnetically induced transparency (EIT) is discussed. As an example of this, simulation on a tunable photonic crystal slab exhibiting negative refraction is presented.
We report on the synthesis and characterization of crystalline InP and Ga2O3 nanowires. The nanowires are synthesized using a simple method based on vapor-liquid-solid (VLS) growth; a method we believe could form the basis of cheap and simple fabrication of crystalline nanowires of a broad range of semiconductor materials, including III-V compounds and semiconductor oxides. The reported InP nanowires have an average diameter of 30nm and the Ga2O3 nanowires diameters down to 100nm. Characterization data including SEM, XRD, TEM and PL are presented.