We design and theoretically analyze a heterojunction bipolar transistor (HBT) electro-optic (EO) modulator with a composition graded SiGe base. The waveguide has a large cross-section of 1µm for ease of fiber alignment. At a base-emitter bias of V BE = 2.5V, a π-phase shift requires 74.5µm interaction length for TM polarization at λ = 1.55µm. The total… (More)
A SiGe electro-optic modulator operating at wavelength of 1.55 microm is proposed. The "ON" state voltage is set at 1.4V. The arm of the MZI waveguide required to generate a pi phase shift is 73.6 microm, and the total attenuation loss is 3.95 dB. The rise and fall delay time is 70.9 ps and 24.5 ps, respectively.
The development of a new hybrid packaging method is reported, where the front end radio frequency (RF) element, namely a modified quasi-Yagi antenna, is integrated with an optical transmitter and an optical receiver on single PCB for dual-mode, i.e. RF/free space optical communication. The VCSEL and the pin diode are placed on the antenna directors to share… (More)
Electrically controlled wavelength switchable terahertz band pass filter based on photonic crystal structures with LC defect layer is proposed and discussed. The wavelength switching can be realized by reorienting liquid crystal molecules through adjusting the applied electric field. Numerical analyses results have shown that the proposed structure has the… (More)
This paper proposes to use slow light effects near the Brillouin zone band edge of one-dimensional gratings for reducing the size of integrated electro-optic (EO) modulators. The gratings are built within the arms of a Mach-Zehnder Interferometer (MZI) for intensity modulation. To overcome the inherent high reflection and low extinction ratio, we introduce… (More)
A free space optical (FSO)/radio frequency (RF) dual mode communication transmitter using a LED integrated within the geometry of a planar patch antenna on a shared substrate is demonstrated. An experimental FSO link is constructed with a bare die visible LED and a commercial silicon photodetector. The antenna radiating at a centre frequency of 10 GHz,… (More)
—This paper presents new results on integrated devices for radio and free-space optical dual-mode communication. Two novel hybrid packaging schemes using two different microwave printed antenna designs are presented for the integration of radio-optical front-end circuits on a planar compact printed circuit board with shared electrical and structural… (More)