H. L. Garvin

Channel optical waveguide directional couplers

We report the first demonstration of channel optical waveguide directional couplers. The closely spaced channel waveguides were fabricated in GaAs by proton implantation. Optical coupling was observed at 1.15 μ with complete light transfer out of the initial channel into adjacent channels in lengths of typically 2 mm.

Optically pumped GaAs surface laser with corrugation feedback

A GaAs distributed‐feedback laser was fabricated and pumped optically. A narrow stimulated spectrum was obtained around 0.83 μ with threshold pumping power of ∼2 × 105 W/cm2.

Ion beam micromachining of integrated optics components.

Thin film integrated optics components such as light guides, modulators, directional couplers, and polarizers demand high quality edge smoothness and high resolution pattern formation in dimensions down to submicrometer size. Fabrication techniques combining holographic and scanning electron beam lithography with ion beam micromachining have produced planar phase gratings with intervals as small as 2800 A, guiding channel couplers in GaAs, and also wire- grid polarizers for 10.6-,microm radiation.

Laser oscillation in epitaxial GaAs waveguides with corrugation feedback

Laser action was observed in GaAs epitaxial films using corrugation feedback. The output wavelength was found to depend on the corrugation period. The loss, threshold gain, and feedback parameters were determined and compared with theoretical predictions.

Channel Optical Waveguides and Directional Couplers in GaAs–Imbedded and Ridged

Two-channel imbedded directional couplers were fabricated with proton implantation, yielding complete light transfer in 2 mm. Ridged channel guides were fabricated by ion-micromachining epitaxial layers, and a method of directional coupling was demonstrated.

Dot lithography for zero‐dimensional quantum wells using focused ion beams

A 50‐keV focused Ga+ beam formed in a two‐lens microprobe column with prefinal lens deflection was used to expose dot arrays in a negative acting bilevel resist. Dot arrays 600 μm×600 μm with 600‐A‐diam resist posts on 0.6 μm centers (incorporating 1024×1024 dots) were fabricated with ion exposure times of 18 s. By reducing the beam dwell time by a factor of 2, roughly 300‐A‐diam posts were fabricated. Since the ions stop in the bottom resist layer and do not enter the substrate, the optical properties of underlying material should not be altered by damage from the exposure process.

Optically pumped GaAs waveguide lasers with a fundamental 0.11 μ corrugation feedback

Abstract Surface corrugations with a period of 0.115 μ were ion-milled on GaAs dielectric waveguides. Laser action was observed under optical pumping. Single mode as well as multimode oscillation was obtained under different pumping conditions.

Ion-Etched Gratings For Laser Applications

Ion beam sputter etching has proven to be a superior technique for producing grating sampling mirrors for large optical systems. The patterns to be etched are defined by a photoresist masking film on the mirror surface. Grating patterns have been produced on laser mirrors by replication of diamond-scribed master patterns, while holographic construction has been used to produce linear and nonlinear gratings. The microscopic details of ion etched grating profiles show that the process is capable of high resolution pattern delineation and large area device fabrication.

Holographic Surface Grating Fabrication Techniques

Diffraction gratings on the surfaces of optical substrates have been demonstrated to perform functions such as beam sampling and infrared polarization. These surface gratings are defined by holographic exposure and ion beam sputter etched into a gold layer on the substrate. The patterns can be designed with spatially varying periods to provide optical power in the diffracted beam and they can cover large areas on flat or non-flat surfaces. High grating accuracy and edge definition result in improved performance when compared to conventional fabrication techniques.

Panel Discussion On Grating Technology

CC: I would like to ask the panel four questions of general interest, and since our time is rather limited, I would like to ask you to try to limit your comments to three or four minutes. The questions are the following: 1. How would you characterize the progress of grating technology over the past 5 years, particularly in the area of theoretical analysis, experimental applications, and diagnostics? 2. What are the areas that need innovative ideas and technical break-throughs. This question is addressed more for the benefit of younger people. Suppose we have, for example, a Ph.D. student wanting to do a thesis; in what areas would you like to suggest they put their study time in? 3. What are the major problems in the grating technology community? Do they include funding, work force (are we educating enough talent in the Universities?), industrial secrecy, government assistance, international cooperation, patent protection, or any other items? 4. What actions can you suggest to promote the welfare of the grating technology community? Has it been worthwhile to come to this conference? Are there some things that we can change? What recommendations do von feel we should make?