Facilities

Multimodal Nonlinear Optical Microscopy

Includes Coherent anti-Stokes Raman Scattering (CARS), multi-photon excited (MPE) fluorescence, and second/third harmonic generation (SHG/THG) microscopy.Layered structure depth profile images of liquid crystal samples between two cover slips obtained by the three photon excited fluorescence technique.Experimental setup for the multimodal nonlinear optical microscopy of multiphoton excitation fluorescence (MPEF) and second harmonic generation (SHG) imaging. A femtosecond pulse from a tunable Ti:Sapphire osc...

Laser Scanning Confocal Microscopy

Fluorescence confocal microscopy (FCM) with 5 different laser excitation lines, fluorescence microscopy, fluorescence confocal polarizing microscopy (FCPM), polarizing microscopy (PM), high-speed PM and bright-field imaging up to 200,000 fps.  FCPM image of liquid crystal structures.Dong-Ki Yoon and Christopher Twombly collecting 3D images of a liquid crystal sample using FCPM.

Holographic Optical Tweezers

An image showing 3D manipulation of colloids in water.Ryan Young and Michael Varney adjusting the setup for manipulation of particles in a liquid crystal cell.

Structural Illumination for Light-Controlled Manipulation of Matter

Opto-elastic translation of colloidal chains in a liquid crystal sample.Angel Martinez at the bench, with Heather Loden and Hector Mireles discussing experimental results.

Diffractive Optics Characterization

2D diffraction pattern from an array of Torons in a liquid crystal sample.Ruwang Sung and Paul Ackerman showing liquid crystal based diffractive optics.

Nanoparticle Synthesis

Gold nanorods obtained in the lab.Julian Evans and Corinne Beier synthesizing well defined nanoparticles of various shapes.

Biological Sample Preparation and Storage

Periodic pattern of liquid crystalline phase of DNA.Pegah Naeimi storing biological samples in the ULT freezer.

Laser Scanning Optical Trapping System

Measurement of defect line tension.The set-up allows three dimensional (3D) optical trapping implemented using an electrically addressed spatial light modulator along with 3D imaging of the sample using fluorescence confocal polarizing microscopy (FCPM). The beam from a 1064 nm CW laser is first expanded by a telescope in the optical to match the beam size to the active area of the electrically-controlled, phase-only spatial light modulator (SLM). Upon being reflected off the SLM, the beam is again resized ...

Two-Photon Photopolymerization for Fabrication of Complex-Shaped Particles and Structures

We photopolymerize complex-shaped particles within glass cells consisting of a standard microscope slide and a 170 μm-thick coverslip, spaced by 50 μm-thick strips of Mylar films. The cell is “sandwiching” a droplet of photoresist. The multiphoton polymerization setup consists of a tunable femto-second pulsed Titanium:Sapphire laser operating at wavelength of 780 nm, piezo-electric nano-positioning stage (Physik Instrumente, model P-611.3SF, 0.2 nm resolution), and a fast shutter (Uniblitz, model LS3Z2, 200...

Simultaneous Holonomic Magnetic and Holographic Optical Manipulations

Full Holonomic control of colloidal particles is achieved by combining mostly rotational magnetic manipulation with translational manipulation by holographic optical tweezers (HOT) in a single integrated setup shown in the Figure. This allows us to define arbitrary positions and orientations of individual and multiple particles of interest. The HOT is built using a fiber laser operating at 1064 nm with output powers of up to 10 W. The trapping beam passes through a polarizer (P), two lenses (L1, L2) forming...

Multifunctional Raman Micro-Spectroscopy

Multifunctional Raman micro-spectroscopy is implemented using an inverted microscope (IX-71, Olympus), SpectraPro-275 spectrometer (Acton Research Corporation), an electron multiplying charge coupled device (EMCCD, iXon3 888, Andor Technology), and a continuous-wave 532-nm laser. The system includes a single beam optical trapping using 1064 nm laser beam, rotating particle detection, 3D particle tracking using DH-PSF (double helix- point spread function) and a magnetic tweezers system as well as the Raman m...

Stimulated Raman Scattering Polarizing Microscopy

In SRS-PM, two beams, pump (at frequency ωp) and Stokes (at frequency ωs < ωp), combine to amplify the Stokes Raman signal when the difference between ωp and ωs equals the vibrational frequency (ωvib) of a certain chemical bond in the molecules [Figure (a)]. As a result of the amplification of the Raman signal, the pump beam experiences a loss in its intensity, dubbed “stimulated Raman loss” (SRL), while the Stokes beam experiences a gain in its intensity, dubbed “stimulated Raman gain” (SRG). Since the gai...

Cleanroom Facility

Includes a spin coater, plasma cleaning, ion etching, sputtering, glove box, sonifier, etc.Helical filaments of a B7 bent-core liquid crystal confined in a channel geometry.Tyler Wingfield preparing a liquid crystal thin film on a substrate using a high speed spin coater.