EOSpace Inc. Patent applications |
Patent application number | Title | Published |
20160043803 | High-RF-Frequency Analog Fiber-Optic Links using Optical Signal Processing Techniques - Wide band phase modulators used with high power laser carriers convert high-frequency RF signals to phase-modulated optical signals. Higher laser optical power to the modulator produces larger RF signal sidebands. A carrier attenuation filter passes the attenuated carrier and non-attenuated RF modulation sidebands. Carrier attenuation leaves the larger RF signal sidebands. A demodulation filter used with a photodetector or a balanced photodetector pair converts the phase-modulated optical signal back to an electrical signal. Carrier-only attenuation allows high power laser use, avoids photodetector damage or saturation, and provides increased RF link gain, low noise figure (NF) and high spurious-free dynamic range (SFDR). Filtered-out carrier power fed back to the laser source increases to overall system efficiency. An additional optical delay filter with dual outputs used with a polarization multiplexer or a coherent combiner coupler combines signal power to a single photodetector to further increase electro-optic signal conversion efficiency. | 02-11-2016 |
20140205229 | Advanced Techniques for Improving High-Efficiency Optical Modulators - Improved optical interferometric modulators have a small waveguide spacing so that the waveguide pair are close to the central electrode, to enhance electro-optic interaction. Asymmetric waveguides with differential indices are used to effectively de-couple the waveguide pair. Multiple sections of asymmetric waveguide pairs with alternating differential indices are used to achieve chirp-free operation. Another version of the device utilizes transmission-line electrode that weave closer to one of the waveguide pair alternately between sections. Another version of the device utilizes waveguide structure that one of the waveguide is closer to the central electrode in alternate section. To improve efficiency further, a DC bias is provided on the outer electrodes configured as an RF-ground but DC-float electrodes. Another improvement is to have a slot is cut underneath the waveguide region to effectively reduce to thickness of the substrate. These improvements lead to higher modulator efficiency. | 07-24-2014 |