Optical-fiber-to-waveguide coupling using carbon-dioxide-laser-induced long-period fiber gratings

Abstract

Optical fibers are expected to play a role in chip-level and board-level optical interconnects because of limitations on the bandwidth and level of integration of electrical interconnects. Therefore, methods are needed to couple optical fibers directly to waveguides on chips and on boards. We demonstrate optical-fiber-to-waveguide coupling using carbon-dioxide laser-induced long-period fiber gratings (LPFGs). Such gratings can be written in standard fiber and offer wavelength multiplexing-demultiplexing performance. The coupler fabrication process and the characterization apparatus are presented. The operation and the wavelength response of a LPFG-based optical-fiber-to-waveguide directional coupler are demonstrated.

An Improved Design of Pressure Relay Based on Optical Switch

“…ON OPTICAL SWITCH This paper proposed a method of improving pressure relay (shown as Figure.1). A reflection optical switch was added to the precision pressure gauge (shown as Figure.2) [5][6]. The reflection optical switch was fixed to the circular guide (shown as Figure.3).…”

Spot-Size Converter Based on Long-Period Grating

“…As is well known, at resonance wavelengths, an LPG can couple the mode of the cladding into the mode of the core completely and vice versa [19], [20]. By exploiting this unique capability, LPG-based wavelength filter [21]- [23], mode filter [24], [25], mode switch [26], mode converter [27]- [30], grating coupler [31], and optical-fiber-to-waveguide coupler [32] have been proposed and demonstrated recent years. Note that the transfer of light power between the fiber and the waveguide in [32] is based on the grating-assisted transverse coupling, not butt coupling via the facets of the fiber and the waveguide.…”

“…By exploiting this unique capability, LPG-based wavelength filter [21]- [23], mode filter [24], [25], mode switch [26], mode converter [27]- [30], grating coupler [31], and optical-fiber-to-waveguide coupler [32] have been proposed and demonstrated recent years. Note that the transfer of light power between the fiber and the waveguide in [32] is based on the grating-assisted transverse coupling, not butt coupling via the facets of the fiber and the waveguide. Similarly, this unique transverse mode coupling capability of an LPG can also be exploited to achieve the conversion between a small-size core mode and a large-size cladding mode and, hence, realize the SSC.…”

Arc-Induced Long-Period Fiber Gratings at INESC TEC. Part II: Properties and Applications in Optical Communications and Sensing

“…The use of LPFGs for dark hollow beam generator [ 17 ], or as mode converters in standard fibers [ 18 ], two-mode fibers [ 19 , 20 ] and as wavelength selective polarizers [ 21 , 22 , 23 , 24 , 25 , 26 ] has also been demonstrated. LPFGs can be used to enhance coupling between fiber and a waveguide [ 27 ], a semiconductor laser or a bulk optical element [ 28 ]. Coupling between a fiber and the free space by producing a planar wave was also demonstrated [ 29 ].…”