Research Projects
Project | 01
Project | 01 Thermal effects of Ultrafast laser material interaction of polymers
Ultrafast lasers have been used for high-precision processing. To make ultrafast laser materials processing compatible with the scale and throughput needed for industrial use, it is a common practice to run the laser at a high repetition rate and hence high average power. However, heat accumulation under such processing conditions will deteriorate the processing quality, especially for polymers, which typically have a low melting temperature. It is found that heat accumulation can be avoided by a proper choice of the processing condition.
Project | 02
Project | 02 Absorption and temperature distribution during ultrafast laser micro-cutting of polymeric materials
Material processing by ultrafast lasers is an attractive technology for high-precision fabrication, such as cutting, drilling, and surface modification, of a wide range of material, including dielectrics, semiconductors, metals, and polymer composites. However, it is still challenging to apply ultrafast laser processing in many applications because some key processes, such as absorption and heat accumulation, are not fully understood, especially for polymeric materials, which have a low melting temperature and, therefore, are more vulnerable to thermal damage.
Project | 03
Project | 03 Time-resolved measurements of Optical properties in ultrafast laser interaction
The optical properties of materials changed during the ultrafast laser interaction with laser. Time-resolved, single-shot measurements are performed to determine the reflectance, transmittance, and absorptance in ultrafast laser interaction with polypropylene for a wide range of laser pulse energies yourself by using a new method by using ellipsoidal mirror .
Project | 04
Project | 04 To understand the ultrafast laser interaction mechanism with polymers
The behavior of ultrafast laser interaction with transparent and opaque polymer is distinct from each other due to the different interaction mechanisms involved when ultrafast laser pulses are irradiated on the sample. In addition, the dynamics of ultrafast laser interaction with the polymer in the near-infrared wavelength is still challenging to understand due to the complicated linear and nonlinear absorption mechanisms. The absorption mechanism was studied by performing time-resolved measurements of ultrafast laser interaction with opaque and transparent polymers .
Project | 05
Project | 05 Investigating optical behavior change during ultrafast laser-material interaction with polymers
Polymers were one of the first materials to be processed by ultrafast lasers. However, the nature of absorption for near-infrared laser beams is not fully understood, and therefore, it remains challenging to process polymeric materials with high energy-efficiency. In this study, the pulse-to-pulse evolution of optical properties (reflectance, transmittance, absorptance) of polypropylene (PP), which is a polymeric material widely used in many industrial applications, is determined by performing time-resolved measurements from pulse to pulse for a wide range of pulse energies.
Project | 06
Project | 06 Study cellular and molecular study with two-photon microscopy
Advances in microscopy and fluorescent probes provide new insight into studying cellular and molecular interactions. Two-photon fluorescence microscopy is one of the most important recent inventions in cellular and molecular study. This technology enables noninvasive study at cellular and molecular levels in three dimensions with sub-micrometer resolution. Two-photon excitation of fluorophores results from the simultaneous absorption of two photons. This excitation process has a number of unique advantages, such as reduced specimen photodamage and enhanced penetration depth.
Project | 07
Project | 07 Laser Raman Spectroscopy with Different Excitation Sources and Extension to Surface Enhanced Raman Spectroscopy
A dispersive Raman spectrometer was used with three different excitation sources (Argon-ion, He-Ne, and Diode lasers operating at 514.5 nm, 633 nm, and 782 nm, resp.). The system was employed to a variety of Raman active compounds. Many of the compounds exhibit very strong fluorescence while being excited with a laser emitting at UV-VIS region, hereby imposing severe limitation to the detection efficiency of the particular Raman system. The Raman system with variable excitation laser sources provided us with the desired flexibility toward the suppression of unwanted fluorescence signal.
Project | 08
Project | 08 Fiber to Fiber coupling for Fiber laser applications
The project was designed to see the best performance on complying with the laser beam from fiber to fiber coupling in Fiber laser applications using the same NA values or different NA values. Zemax design is shown in the figure and the efficiency with different design
Project | 09
Project | 09 Pump and signal detection system
for fiber laser application
The detection system is designed to check pump and signal coupling by using different optical components as shown in figure