Current sate-of-the-art electronic analog-to-digital converters (ADCs) operating at multi gigahertz sampling frequencies are known to exhibit fairly limited resolution. These high-frequency restrictions stem primarily from the response time of the constituent transistors that make up the ADCs comparators. In an effort to improve the resolution of ADCs operating at ultrahigh sampling frequencies, several areas of investigation are currently underway regarding the capabilities of hybrid optoelectronic systems. High-power optical pulses can be used as sampling windows and high- bandwidth electro-optic modulators as voltage-to-intensity transducers to provide a means for digitizing ultrafast voltage waveforms with much greater accuracy than conventional ADCs. When optical sampling is employed, the primary limiting factors determining ADC conversion accuracy becomes the noise in the sampling pulse train and the extent of the sampling time. Detrimental pulse train noise is associated with either phase modulation or amplitude modulation, and recent measurements of AM and residual PM noise on our 10 Ghz ring laser show the best results to date for an actively-mode-locked semiconductor diode system. Carrier offset integration bands extending form 10 Hz to 10 MHz exhibit RMS levels of AM and PM noise as low as 0.12 percent and 43 fs, respectively. In addition, linear dispersion compensation has successfully reduced the optical pulsewidth from 13 ps to 1.2 ps. Based on these experimental numbers, this laser could form the front end for an optoelectronic ADC capable of a theoretical resolution as high as 8.6 bits.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.