A compact high-speed tuning laser source is demonstrated in two different configurations using a polygonal mirror scanner without a telescope. It is shown that the filter configuration finesse increases by utilizing multiple reflections from the polygon facet(s) and grating illumination(s). Theoretically, the free spectral range (FSR), the instantaneous linewidth, and the finesse of each filter configuration are derived. For single grating illumination, the measured coherence length, FSR, and power were $2.8\mathrm{mm}$ , $184\mathrm{nm}$ , and $40\mathrm{mW}$ at the scanning frequency of $50\mathrm{kHz}$ , respectively. Coherence length, FSR, and power of the second laser configuration were $6.2\mathrm{mm}$ , $117\mathrm{nm}$ , and $35\mathrm{mW}$ , respectively. Finally, images of a human finger were acquired in vivo using two proposed swept-source configurations.