Holografik optik cımbızlama seti yapımı

Since its discovery in mid-80s by Arthur Ashkin, optical tweezing has undergone an important breakthrough and expanded its horizons. Nowadays optical tweezers application in many fields, from biology to nanotechnology, is inevitable. Investigating mechanical properties of DNA, protein-DNA interactions, carbon nanotubes properties are among a few major examples of successful applications of optical tweezers. The next milestone in optical tweezing was trapping several particles simultaneously. Advent of spatial light modulator (SLM) paved the way for this purpose in holographic optical tweezers (HOT). In fact, although many devices can be considered as SLM, liquid crystal (LC) devices play a significant role in HOT systems. LC-SLM enables creating and manipulating several traps simultaneously and independently. To put it another way, HOTs are like our fingers in microscale. In this thesis, I try to explain construction of holographic optical tweezer set-up in Istanbul technical university and major obstacles that we had to overcome, as several modification were done in single particle trapping set-up such as using different Keplerian telescopes etc. One of the most important factors was calibration of the LC-SLM, since this device in default company configuration may function in unwanted phase shift interval. I have also developed an interactive graphical user interface (GUI) in MATLAB and Simulink Student Suite 2014a in order to manipulate micron-sized particles in 3D. This program is able to get several traps positions from user and generate the desired trap holograms, in a way that, each trap can be manipulated in 3D independently. In this program, I have exploited the most straightforward and fastest method, which is gratings and lenses algorithm (G&L). The program calculates the hologram after placing the spots in a region, which shows the sample plane by camera. Created hologram image in the object plane is transformed to image plane using Fourier transform via suitable number of lenses. For our future works, additional application were also implemented in this program in order to take a spot from initial coordinates to a desired coordinates with a speed and step numbers all defined by user. In addition to these, several other measurements either in calibration or HOT set-up were done to achieve better adjustments.