HCG tunable VCSEL system with ASIC for processing information and firmware

An optical coherence tomography (OCT) system, comprising:

• a tunable VCSEL system, comprising:
• a tunable VCSEL including:
• a first mirror;
• one or more active regions with a first active region adjacent to the first mirror, each of an active region including quantum wells and barriers, each of an active region surrounded by one or more p-n junctions, the one or more active regions including a selected shape structure each with a tunnel junction (TJ);
• one or more apertures provided with the selected shape structure;
• one or more buried tunnel junctions (BTJ), additional TJ's, planar structures and/or additional BTJ's are created during a regrowth process that is independent of a first growth process of the first mirror, the active region and the one or more TJs;
• one or more electrical confinement apertures defined by the one or more BTJ's, additional TJ's, planar structures and/or additional BTJ;
• a vertical resonator cavity disposed over the electrical confinement aperture;
• a high contrast grating (HCG) operating as a second mirror positioned over the vertical resonator cavity, the HCG configured to reflect a first portion of light back into the vertical resonator cavity, and a second portion of the light as an output beam from the VCSEL, the HCG structure being layered on the selected shape structure;
• wherein a shape of the output beam of the tunable VCSEL laser is determined by a geometric shape of the one or more BTJ apertures, apertures for additional TJ's, planar structures and/or additional BTJ's, with a transmission function of the HCG and is designed according to the desired optical transmission function of the application;
• and
• an interface medium at a distal end of an optical fiber;
• a lens in optical contact with the interface medium, the lens configured to focus optical radiation through the side-opening window to a focal point in the target,
• wherein a beam diameter at the focal point is between 10 and 60 microns;
• receiving electronics configured to receive the optical radiation reflected from the interface medium and the target;
• and
• a processor to generate an image of the target based upon the optical radiation received by the receiving electronics.