| Squeezed states have long been recognized as a means of increasing the sensitivity of precision measurements that are limited by quantum noise. Nonlinear quasi-phasematched waveguides offer several advantages for squeezed state generation, compared to conventional bulk nonlinear crystals. Issues related to squeezing in waveguides are discussed in this dissertation. In particular, we have observed a squeezed vacuum state generated in a quasi-phasematched lithium niobate waveguide.; In an effort to make this dissertation self-contained and accessible to a larger audience, theoretical analyses pertaining to the generation and detection of squeezed states have been included. The classical theory of nonlinear optics in waveguides is reviewed, yielding quantitative predictions of second-harmonic generation and degenerate parametric amplification. The quantum theory of the degenerate parametric amplifier shows that it produces a squeezed vacuum state. The quantum theory of homodyne detection indicates how a squeezed vacuum state can be observed.; Experimental measurements of mode-locked second-harmonic generation and degenerate parametric amplification are presented. A second-harmonic conversion efficiency of 20% was observed with a mode-locked-average fundamental power of 7.5 mW at 1064 nm inside the waveguide. A parametric gain of 1.9 was observed with a mode-locked-average pump power of 0.75 mW at 532 nm inside the waveguide, which agrees with the measured second-harmonic conversion efficiency factor of 0.4 W{dollar}sp{lcub}-1{rcub}{dollar}. Finally, a squeezed vacuum state was produced, with the observed variance in one field quadrature reduced 14% below the vacuum state level. The observed squeezing implies that the variance inside the waveguide was reduced by 35%, in close agreement with the measured parametric deamplification.; The appendix contains a detailed analysis of electrically-resonant detectors, which to the author's knowledge is not currently available in the literature. The resonant circuit formed by the photodiode junction capacitance and an external inductor is shown to increase the output signal from the detector by a factor of the impedance-matched Q, which was 8 for our circuit. Such a signal enhancement is important for squeezing experiments, since the detector output typically lies only slightly above the thermal noise floor. |
