Jin-ha Kim

Polymeric waveguide prism-based electro-optic beam deflector

Beam steering devices without moving parts are highly desir- able for their potential application in emerging optical technologies such as holographic optical storage systems, all optical networks, and optical switches. We demonstrate a thin-film waveguide beam deflector device that consists of an electro-optic prism array within a polymer waveguide. An electrode structure defines the prism array within the planar wave- guide. The deflection efficiency of 28 mrad/kV and the maximum deflec- tion angle of 68.4 mrad at 6300 V are obtained for this demonstration device. Further optimization of electrode-field poling and processing is likely to improve these results by at least an order of magnitude.

Polymer-based thermo-optic waveguide beam deflector with novel dual folded-thin-strip heating electrodes

A new design scheme for a polymeric waveguide thermo- optic beam deflector is presented and experimentally demonstrated. The refractive indices of the waveguide materials can be thermally tuned by applying electric current through a metal thin film electrode deposited and patterned using standard lithography on top of the waveguide. In doing so, the geometry of the electrode determines the performance and reliability of the beam deflector. We form a pair of heating electrodes sitting opposite to each other like interlocked sawteeth that have a folded-thin-strip substructure, and hence demonstrate an advanced beam deflector that has biangular sweeping capability, low power con- sumption, less wavefront distortion, and high reliability. A full sweep angle of 56.5 mrad (3.24 deg) and 138 switching capability at a 1550 nm wavelength are attained with an average power consumption of 247 mW per switching between adjacent resolvable spots. Switching from the zero-bias spot to the first resolvable spot exhibits a response time of 2 ms in both rising and falling.

A collimation mirror in polymeric planar waveguide formed by reactive ion etching

We fabricated and characterized an integrated optical mirror in a polymeric waveguide. A parabola-shaped cavity is etched in fluorinated polyimide using oxygen reactive ion etching. The vertically etched sidewall of the planar waveguide works as a highly reflecting total-internal-reflection mirror, which collimates a diverging beam from its focus. The estimated mirror insertion loss of the demonstrated device is 2.4 dB or less.

An integrated thin-film thermo-optic waveguide beam deflector

We have demonstrated the operation of a thin-film thermo-optical beam deflector in a three-layer optical planar waveguide. The fabricated waveguide beam deflector consists of a thin-film SiO2 bottom cladding layer, a thin-film polymer top cladding layer, and alternatively positioned thin-film polymer and silica microprisms as the guiding layer. The beam deflection is achieved through the thermo-optic effect that results in opposed index changes in polymer and silica with respect to temperature changes. The measured deflection sensitivity is 0.06°/°C, for the fabricated device with a 7.0 mm interaction length at the wavelength of 632.8 nm.

A thin-film polymeric waveguide beam deflector based on thermooptic effect

A thin-film polymeric waveguide beam deflector was fabricated and demonstrated. The three-layer planar waveguide was composed of UV15 as the top cladding layer, a polyimide as the core layer, and SiO/sub 2/ as the bottom cladding layer on a silicon substrate. A gold layer was deposited on the top of the waveguide by e-beam deposition and then patterned into a prism-array as the heating electrode by photolithography. Beam deflection was acquired by passing the beam through the waveguide underneath the prism array. The beam deflection angle showed the expected quadratic dependence upon the applied voltage. A maximum acquired beam deflection angle of 2.5/spl deg/ was derived at an applied voltage of 8 V. Eight resolvable spots were observed, which made possible the feasibility of a 1/spl times/8 optical switch.

Polymetric waveguide beam deflector for electro-optic switching

We fabricated and demonstrated a beam deflector implemented in an electro-optic polymer planar waveguide. An array of prism- shaped electrodes formed on the top of the waveguide induces selective refractive index change in the core polymer layer, which results in the tilt of the propagation direction of the guided beam. Waveguide beam deflectors have potential applications in the emerging photonics technologies such as optical storage systems, optical phased array antenna, and optical switching. The deflection sensitivity of 28 mrad/kV, and the maximum deflection angle of +/- 8.4 mrad at +/- 300 V were obtained for this first demonstrated device.

Beam deflection with electro-optic polymeric waveguide prism array

A beam deflector device has been demonstrated that used thin-film electro-optical polymeric waveguide. Prism cascade was fabricated within a planar waveguide. We report the detail of the design and fabrication of new polymer material beam deflector to operate at 1.3 micrometers .

Silicon Modulators Based on Photonic Crystal Waveguides

Ultra-compact silicon-photonic-crystal-waveguide-based thermo-optic and electro-optical Mach-Zehnder interferometers have been proposed and fabricated. Thermal and electrical simulations and optical characterizations have been performed. Experimental results were in good agreement with the theoretical predictions.

Thin film polymeric waveguide beam deflector based on thermo-optic effect

In this paper, we demonstrate a thin-film polymeric waveguide beam deflector using a new device concept, an electrode of prism-array pattern on top of a three-layer planar waveguide. The three-layer planar waveguide was composed of UV15 as the top cladding layer, a polyimide as the core layer, and SiO2 as the bottom cladding layer on a silicon substrate. A gold layer was deposited on the top of the waveguide by e-beam deposition and then patterned into a prism-array as the heating electrode by photolithography.

Novel guided-wave thermo-optic beam deflector

A novel approach for laser beam deflection using the thermal optic prism array in a polymeric planar waveguide is developed. This approach is based on the different thermo- optic properties between polymer and silica, the two optical materials employed for the guided wave beam deflector. A waveguide structure with the core layer composed of inversely positioned polymer and silica triangles forming a polymer/silica prism array has been fabricated. Through electrical heating, a temperature change results in an index difference between the two optical materials and creates an optical prism structure in the polymer/silica planar waveguide. A beam deflection of 5.4 degree was observed under a temperature change of 60 degrees C in the fabricated prism array. The sensitivity of the device is 0.09 degrees/degrees C. A maximal number of resolvable spots of 8 was achieved at a low driving power from the thermo-optic prism array structure. The accuracy of beam deflection approaches 16 micro-radian. The device fabricated has a thickness of 5 microns, a prism aperture width of 600 microns, and a device length of 7 mm. Optimal design to maximize the deflection angle and the number of resolvable spots has been evaluated.