Abstract:
A compact and low cost of Optical Tweezers usually uses diode lasers. Diode lasers are widely used because of their small size, broad wavelength variations and low cost. Howover, they have some disadvantages such as laser elliptical beam shape and vulnerable to electrical current fluctuations. In this research, a current regulator circuit system was designed and made which composed of a power supply circuit,three current
regulators, and a current-limiting circuit. This system was used to regulate the electric currents injected into three laser diodes i.e type HL6312G with wavelegth 635 nm, type L780P01 with wavelegth 780 nm, and type WSLP-785-030m-4-PD with wavelegth 785 nm. From the results, variations of voltage and current versus time were obtained, electric current and power stability of the laser diodes versus time were observed for 60 minutes. Fluctuations obtained for all three circuits regulating electric current was
about ± 0.001 mA. Variation of electric current for the laser diode to the three power laser diodes successfully obtained with current and power ranges were 12,2 mA to 76,6 mA and power from 0 mW to 4,55 mW for laser type HL6312G, current range 5,7 mA-40,0 mA and power from 0 mW to12,54 mW for laser type L780P010, current range 17,9 mA-129,9 mA and power from 0 mW to19,24 mW for laser type WSLP-785-030m-4-PD, respectively
