  FDML lasers provide sweep rates in the MHz range at wide optical bandwidths,
making them ideal sources for high speed OCT. Recently, at lower speed,
ultralong-range swept-source OCT has been demonstrated1, 2 using a tunable
vertical cavity surface emitting laser (VCSEL) and also using a Vernier-tunable
laser. These sources provide relatively high sweep rates and meter range
coherence lengths. In order to achieve similar coherence, we developed an
extremely well dispersion compensated Fourier Domain Mode Locked (FDML) laser,
running at 3.2 MHz sweep rate and 120 nm spectral bandwidth. We demonstrate
that this laser offers meter range coherence and enables volumetric long range
OCT of moving objects.
