Characterization of SiN/SiO2 based MEMS-VCSEL at 1550 nm for optical coherence tomography

Due to its superior imaging performance Swept Source Optical Coherent Tomography (SS-OCT) has become an established 3D imaging methodology. One of the key elements of this technique is the swept source as its tuning range and tuning speed will define the axial resolution and the time required to acquire an A-scan. This work presents the characterization of the performance in SS-OCT of an electrically pumped Microelectromechanical Movable Mirror Vertical Cavity Surface Emitting Laser (MEMS-VCSEL) in the range from 1540-1600nm. To investigate the tuning performance of the MEMS-VCSEL its output signal is amplified with and Erbium doped (Er⁺) fiber amplifier connected to an OCT system where the channelled spectrum is processed by using a Complex Master Slave (CMS) method that evaluates the nonlinearity in tuning in both forwards and backwards tuning for tuning frequencies of 10, 50 and 100 Hz. The results obtained show that the linearity of the device increases as the tuning frequency does and it has a sensitivity roll-off at 6dB of 12.65 mm which is equivalent to an instantaneous linewidth of 85pm.