title: Laser output power stabilization for direct laser writing system by using an acousto-optic modulator.
abstract: We present experimental results on the output power stabilization of an Ar(+) laser for a direct laser writing system (LWS). Instability of the laser output power in the LWS cause resolution fluctuations of being fabricated diffractive optical elements or computer-generated holograms. For the purpose of reducing the power fluctuations, we have constituted a feedback loop with an acousto-optic modulator, a photodetector, and a servo controller. In this system, we have achieved the stability of +/-0.20% for 12 min and the relative intensity noise level of 2.1 x 10(-7) Hz(-12) at 100 Hz. In addition, we applied our system to a 2 mW internal mirror He-Ne laser. As a consequence, we achieved the output power stability of +/-0.12% for 25 min.
authors.affiliation: Space Optics Research Center, Korea Research Institute of Standards and Science, 1 Doryong-Dong, Yuseong-Gu, Daejeon 305-340, Republic of Korea.
authors.forename: Dong Ik
authors.initials: DI
authors.lastname: Kim
authors.forename: Hyug-Gyo
authors.initials: HG
authors.lastname: Rhee
authors.forename: Jae-Bong
authors.initials: JB
authors.lastname: Song
authors.forename: Yun-Woo
authors.initials: YW
authors.lastname: Lee
mesh_terms: D000162:Acoustics; D004581:Electronics / Q000295:instrumentation*; D004735:Energy Transfer; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007834:Lasers; D055095:Optics and Photonics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*