Microtubule (MT) ensemble polarity is a diagnostic determinant of the structure and function of neuronal processes. Here, polarized MT structures are selectively imaged with second-harmonic generation (SHG) microscopy in native brain tissue. This SHG is found to colocalize with axons in both brain slices and cultured neurons. Because SHG arises only from noninversion symmetric structures, the u...

Second Harmonic Generation (SHG) has been used in combination with a near-field scanning optical microscope (NSOM) to image biological samples for the first time. Near-field SHG images of azure B stained mouse natural killer (NK) cells were recorded at four different wavelengths using a tunable near-infrared femtosecond laser. The surface specificity of SHG allows membrane structures to be sele...

We report a direct observation on the laterally emitted surface second harmonic generation (SHG) in a single ZnTe nanowire. The highly directional surface SHG radiates vertically to the nanowire growth-axis with a high conversion efficiency of 5 × 10(-6) and a low divergence angle of 4°. Polarization state, emission intensity, and direction of the surface SHG are found to be dependent on the po...

Hysterosonography (SHG) is a new noninvasive technique that involves the slow infusion of sterile saline solution into the uterus during ultrasound imaging. Expansion of endometrial cavity by SHG allows optimal visualization and plays an important role in the evaluation of abnormalities related to the uterus. The most common indications for hysterosonography are: abnormal uterine bleeding both ...

We present a heuristic treatment which relates SHG image intensities, signal directionality, and observed morphology to the physical structure of collagen and cellulose fibrillar tissues. The SHG creation model is based upon relaxed phase matching conditions which account for dispersion, randomness, and axial momentum contributions from the media, and includes a mathematical treatment which rel...

PURPOSE Human corneas with or without stromal edema were examined by second harmonic generation (SHG) imaging microscopy to characterize stromal collagen organization. METHODS Tissue buttons from 31 corneas with stromal edema and 8 normal corneas were fixed, and 3-mm(2) blocks were cut and stained with phalloidin, to visualize the cytoskeleton. The blocks were examined by SHG imaging with a l...

Second harmonic generation (SHG) microscopy is a powerful tool for studying submicron architecture of muscles tissues. Using this technique, we show that the canonical single frequency sarcomeric SHG intensity pattern (SHG-IP) of premetamorphic xenopus tadpole tail muscles is converted to double frequency (2f) sarcomeric SHG-IP in metamorphic climax stages due to massive physiological muscle pr...

Dendritic spines mediate most excitatory inputs in the brain. Although it is clear that spines compartmentalize calcium, it is still unknown what role, if any, they play in integrating synaptic inputs. To investigate the electrical function of spines directly, we used second harmonic generation (SHG) imaging of membrane potential in pyramidal neurons from hippocampal cultures and neocortical br...

We theoretically compare the performance of TPEF and SHG microscopy for membrane potential imaging. We argue that electrochromic TPEF and SHG membrane potential responses are reflections of the same phenomenon, and can be described in a unified manner as resulting from the linear Stark effect. We also show that TPEF and SHG exhibit similar sensitivities in the case of both electrochromic and or...

We demonstrate focusing coherent light on a nanoparticle through turbid media based on digital optical phase conjugation of second harmonic generation (SHG) field from the nanoparticle. A SHG active nanoparticle inside a turbid medium was excited at the fundamental frequency and emitted SHG field as a point source. The SHG emission was scattered by the turbid medium, and the scattered field was...