On-chip optical true time delay lines based on subwavelength grating waveguides

An optical true time delay line (OTTDL) is a fundamental building block for signal processing applications in microwave photonics and communications. Here, we experimentally demonstrate an index-variable OTTDL based on array of 40 subwavelength grating (SWG) waveguides silicon-on-insulator. Each SWG waveguide the 34 mm long arranged serpentine manner; average incremental between about 4.7 ps, total first last approximately 181.9 ps. The occupies chip area ∼ 6.5 m ×<!-- × <mml:mn>8.7 = 56.55 2 . proposed OTTDLs bring potential advantages terms compactness as well operation versatility to variety applications.