Fig. 1.

Contrast agents and PTOCT imaging instrumentation. (a) Extinction spectrum of AuNR samples with an absorption peak of approximately 740 nm, with a representative TEM (inset, scale bar = 100 nm). (b) A fiber-based PTOCT system was constructed for imaging. The titanium sapphire laser was amplitude modulated and used as a photothermal heating source. Mice with dorsal skinfold window chambers containing mammary tumors were intravenously injected with AuNRs into the tail vein and imaged with PTOCT over time. SLD: Superluminescent diode; PC: Polarization controllers; 50/50: Fiber coupler