The paper presents a high-speed, high-sensitivity, and high-resolution optical imaging technique based on optical frequency-domain interferometry (OFDI) using a rapidly-tuned wavelength-swept laser. The authors demonstrate that frequency-domain ranging provides a superior signal-to-noise ratio (SNR) compared to conventional time-domain ranging used in optical coherence tomography (OCT). The OFDI system achieves a sensitivity of −110 dB with a 6 mW source, an axial resolution of 13.5 μm, and an A-line rate of 15.7 kHz, representing a significant improvement over previous OCT and interferometric imaging methods. The system's performance is validated through experimental results, including detailed analysis of the signal and noise components, and comparison with time-domain OCT. The OFDI technique offers advantages in biomedical imaging applications due to its high speed and sensitivity, making it suitable for various medical applications.The paper presents a high-speed, high-sensitivity, and high-resolution optical imaging technique based on optical frequency-domain interferometry (OFDI) using a rapidly-tuned wavelength-swept laser. The authors demonstrate that frequency-domain ranging provides a superior signal-to-noise ratio (SNR) compared to conventional time-domain ranging used in optical coherence tomography (OCT). The OFDI system achieves a sensitivity of −110 dB with a 6 mW source, an axial resolution of 13.5 μm, and an A-line rate of 15.7 kHz, representing a significant improvement over previous OCT and interferometric imaging methods. The system's performance is validated through experimental results, including detailed analysis of the signal and noise components, and comparison with time-domain OCT. The OFDI technique offers advantages in biomedical imaging applications due to its high speed and sensitivity, making it suitable for various medical applications.