No abstract

Single-mode X couplers and three-dimensional waveguides are fabricated in transparent glasses by use of an unamplified femtosecond laser generating energies of up to 100 nJ. Changing fabrication parameters such as power and scanning speed permits creation of waveguides with a wide range of structures and refractive-index difference. Optical coherence tomography shows large refractive-index changes of up to ~10(-2) in the waveguides; these changes are consistent with guided mode analysis.

Ultrahigh-resolution OCT enhances the visualization of intraretinal architectural morphology relative to standard-resolution OCT. Ultrahigh-resolution OCT images can provide a baseline for defining the interpretation of standard-resolution images, thus enhancing the clinical utility of standard OCT imaging. In addition, UHR OCT can provide additional information on macular disease morphology that promises to improve understanding of disease progression and management.

Three-dimensional photonic waveguide devices are fabricated in glass by use of femtosecond pulses from an extended-cavity laser oscillator. Three-dimensional devices, including a symmetric three-waveguide directional coupler and a three-dimensional microring resonator, are fabricated and tested. Waveguides can be fabricated at depths of approximately 1 mm inside a glass substrate, thus demonstrating the capability of achieving dramatic increases in device density. These results demonstrate the potential to fabricate new classes of devices that are not possible in two dimensions.

Coupled mode devices are fabricated in transparent glasses by nonlinear materials processing with femtosecond laser pulses. Using the direct output of an extended cavity femtosecond laser, without the need for a laser amplifier, single mode waveguides can be rapidly fabricated with well controlled parameters. A variety of photonic waveguide devices are demonstrated. Directional couplers with various interaction lengths and coupling coefficients are fabricated and their coupling properties are characterized. Measurements demonstrate coupled mode behavior consistent with theory. An unbalanced Mach-Zehnder interferometer is also fabricated and demonstrated as a spectral filter.