10-GHz and 20-GHz Channel Spacing High-Resolution AWGs on InP

Photonic High-Bandwidth RF Splitter With Arbitrary Amplitude and Phase Offset

“…2b. In practice, the demultiplexer can be implemented using a dedicated waveguide filter, for example an Mach-Zehnder interferometer assisted by ring resonators [18] or an arrayed waveguide grating [19]. According to the system requirements, one can design the filter frequency-domain transmission characteristic H ( f ) to feature flat passbands with symmetrical transition bands on both sides and flat group delays (for example, Chebyshev Type II filters), and incorporate tuning mechanism to enable frequency shifting of the filter.…”

Dynamic optical arbitrary waveform generation and detection in InP photonic integrated circuits for Tb/s optical communications

“…Fig. 9 shows the first generation InP OAWG devices which combine two box-shaped high-resolution AWGs and an array of microwave TW-PM and TW-EAM [43,[47][48][49]. The 10-GHz, 20-GHz, and 40-GHz designs are the exact same size (16 mm× 11 mm) and have the same electrical pad locations to allow reuse of the RF packaging.…”

“…One of the major challenges in these AWG-pair devices was designing fabrication tolerant AWG spectral multiplexers and demultiplexers with 10 GHz and 20 GHz bandwidths and with reasonable adjacent-channel crosstalk (i.e., better than −10 dB) and matching center frequencies [49]. As discussed in Section 1.5, the phase-errors of the AWG determine this crosstalk level and previous InP AWG results in the literature never had a channel spacing less than 25 GHz [51].…”

“…A quick example shows why this is the case. For a 10-GHz AWG, a −10-dB crosstalk level requires that the rms phase error across the arms is less than 30° [49]. This is equivalent to an effective waveguide length variation of~50 nm rms.…”

Ultra-Compact Silicon Photonic 512 × 512 25 GHz Arrayed Waveguide Grating Router

“…Typically the channel count (spectral resolution) of an AWG can be increased by increasing the interference order of the grating or the number of arrayed waveguides and so therefore, AWGs have been used not only for WDM applications, but optical sensing [8], [9] and optical spectrometers [10] as well. Significant work has been done to develop high-performance AWGs based on a number of various material platforms such as buried InP/InGaAsP ridge waveguides [3], [4], [11]- [13], silicon-on-insulator (SOI) ridge waveguides [14], SOI nanowires [15]- [19], silica-on-Si buried waveguides [20]- [22], polymer waveguides [23], and nano-core Si 3 N 4 waveguides [5], [7], [24] TABLE I BRIEF SURVEY OF STATE-OF-THE-ART HIGH RESOLUTION AWG ever, the bending radius is usually very large because of its low index-contrast (∼1.5%) [25] compared to SOI (>40%). For this reason, high density integration on a small footprint is problematic.…”