Graded-index polymer-based waveguide lens working at visible wavelengths on GaAs substrate for optoelectronic interconnects

A polymer-based graded index (GRIN with n= 1.4-1.6) waveguide lens was demonstrated on a semi-insulating GaAs substrate. The transparent bandwidth of the polymer film (photolime gel) is from -280 to -2800 nm. Therefore, UV (ultraviolet), visible and near-IR (infrared) light can be employed as the signal carrier wavelength. In this letter, an off-axis chirped grating lens working at 632.8 nm with 35 mm focal length, 680/mm chirp rate, and angular field of view of 6“ was demonstrated. Measured focal spot size of the main lobe is 5.6 pm which is very close to the theoretical prediction (4.2 pm). The crosslink-induced index modulation is as high as 0.2. Therefore, an array of chirped phase grating lenses can be multiplexed onto the same holographic emulsion for oneand two-dimensional massive fanout optical interconnects and signal processing.