A holographic waveguide microlens array for surface-normal optical interconnects

We present an array of holographic focusing lenses for surface normal optical interconnects. The profile-mismatch-induced coupling problem between input lasers and high-speed photodetectors is solved by employing a holographic microlens array. The holographic microlens array demonstrated has l-mm focal length at the wavelength of 632.8 mm, with a lens-to-lens separation of 0.58 mm. The measured 3-dB focal spot size is determined to be 15 μm×14 μm. The method for designing and recording a substrate mode surface-normal holographic lens array with different recording and readout wavelengths is also presented.