High performance chip-scale OCT at 1310 and 1060nm with module-level integration

Optical coherence tomography (OCT) is a powerful 3D imaging technique commonly used for assessment of retinal pathologies. The high cost and large form-factor of most OCT systems, however, limit its widespread adoption for applications outside of in-clinic ophthalmology, especially in low-resource environments. Advances in optoelectronic integration technology has inspired several chip-scale OCT implementations that could potentially bridge this gap by providing a low-cost, miniaturized, and easy-to-use OCT system for widespread adoption. However, to date these systems have failed to simultaneously show high sensitivity, high imaging rate, and module-level integration. In addition, no previous chip-scale OCT implementation has operated at 1060nm–a key wavelength range for ophthalmic imaging. In this work, we utilize our heterogeneous integrated swept-source OCT platform to demonstrate high-performance imaging at 1310nm and for the first time demonstrate high-sensitivity imaging at 1060nm. We use hybrid integration techniques to package our OCT engine module (2 x 1 x 0.3cm³), which includes a Planar Lightwave Circuit (PLC) photonic chip, integrated balanced photodiodes, collimating ball lens, and co-packaged electrothermally actuated MEMS mirror. The imaging performance of our system is validated with sensitivity measurements, 2D and 3D scans. We report record high sensitivity of 99.6dB at 880μW sample power with our 1310nm OCT chip and a sensitivity of 103.2dB at 2mW using our 1060nm version, both at 100kHz swept-laser repetition rate. These results serve as a major step towards the creation of a low-cost and miniaturized OCT system for widespread application beyond in-clinic ophthalmology.