We report the demonstration of a composite right/left-handed (CRLH) metamaterial waveguide for terahertz quantum-cascade (QC) lasers. By incorporating gap capacitors ( 250 nm) in the top metallization of a metal-metal waveguide operating in a higher order lateral mode, we have realized a CRLH transmission line that supports traveling modes with negative effective phase indices (i.e., left-hande...

We demonstrate an ultra-compact and low-threshold thulium microcavity laser that is monolithically integrated on a silicon chip. The integrated microlaser consists of an active thulium-doped aluminum oxide microcavity beside a passive silicon nitride bus waveguide, which enables on-chip pump-input and laser-output coupling. We observe lasing in the wavelength range of 1.8-1.9 μm under 1.6 μm re...

We present a theoretical roadmap for three-dimensional optical waveguide networks in holographically defined, diamondlike photonic band gap PBG materials. A fully 3D waveguide network is demonstrated through broadband 100–200 nm , single-mode waveguiding in air, coupled with sharp bends in three dimensions with minimal backscattering. Optimal waveguides in the in-plane x and y directions are sh...

For a good THz waveguide, both low propagating loss and small mode width are usually very important. However, the high ohmic loss of metals and the high absorption loss of dielectric materials result in that it still remains a challenge to obtain the two capabilities at the same time. In this paper, planar dielectric-gap-metal (DGM) waveguides are presented to guide THz wave. According to the d...

We experimentally demonstrate a terahertz-bandwidth photonic differentiator employing a silicon-on-insulator directional coupler. The integrated waveguide coupler with two identical paralleled strip waveguides achieves a first-order differentiator when full energy coupling is met from one waveguide to another. The integrated waveguide coupler can offer different operation bandwidths by changing...

An active, photonic band gap-based microcavity emitter in the near infrared is demonstrated. We present direct measurement of the spontaneous emission power and spectrum from a microcavity formed using a two-dimensional photonic band gap structure in a half wavelength thick slab waveguide. The appearance of cavity resonance peaks in the spectrum correspond to the photonic band gap energy. For d...