OCT imaging with temporal dispersion induced intense and short coherence laser source

Abstract

Lower coherence length and higher intensity are two indispensable requirements on the light source for high resolution and large penetration depth OCT imaging. While tremendous interest is being paid on engineering various laser sources to enlarge their bandwidth and hence lowering the coherence length, here we demonstrate another approach by employing strong temporal dispersion onto the existing laser source. Cholesteric liquid crystal (CLC) cells with suitable dispersive slope at the edge of 1-D organic photonic band gap have been designed to provide maximum reduction in coherence volume while maintaining the intensity higher than 50%. As an example, the coherence length of a multimode He–Ne laser is reduced by more than 730 times.

Impact of titanium dioxide nanoparticles on purification and contamination of nematic liquid crystals

“…The area of LCs for non-display applications is also rapidly growing. The application of LCs includes metamaterials [4], photonic crystals [5], plasmonic structures [6], THz devices [7], sensors [8], diffractive optics [9], adaptive lens technologies [10] and vision correction [11], as well as tunable filters [12] and dispersion for imaging [13]. In addition, nanoparticles can induce other new functions in liquid crystals, including improved response time [14–15], surface plasmon resonance [16], and improvements in alignment [17].…”