Full range swept-source optical coherence tomography using 3×3 Mach-Zehnder interferometer with unbalanced differential detection

We present a full range swept-source optical coherent tomography with a 3 x 3 Mach-Zehnder interferometer using a new unbalanced differential optical detection method. The new interferometer provides simultaneous access to complementary phase components of the complex interferometric signal. No calculations by trigonometric relationships are needed. We demonstrate a complex conjugate artifact suppression of 27 dB obtained in a swept-source optical coherence tomography using our unbalanced differential detection. We show that our unbalanced differential detection has increased the signal-to-noise ratio by 7 dB compared to the commonly used balanced detection technique. The suppression of the complex conjugate artifact in our unbalanced detection configurations were 3 dB more than in the commonly used balanced detection method. This is due to better utilization of optical power.