Daniel P. Robinson

Guided-wave planar optical interconnects using highly multiplexed polymer waveguide holograms

An intraplanar interconnection scheme using substrate guided modes in conjunction with a highly multiplexed waveguide volume hologram is proposed. Acoustooptically addressed 1-to-50 passive and 1-to-2-to-100 reconfigurable interconnections with a fan-out diffraction efficiency of 55% at 514-nm wavelength are demonstrated. A coordinate transformation converts the 3-D diffraction problem into a 2-D one, which significantly simplifies the theoretical calculation. Intraplane massive fan-out optical interconnection using substrate guided mode provides both collinear and coplanar fan-out capability for data and clock signals. Colinearity of signal distribution allows the 2-D input signal array to be processes. The laminated waveguide device containing a highly multiplexed dichromated gelatin (DCG) hologram has been evaluated. >

Single-mode Nd/sup 3+/-doped graded-index polymer waveguide amplifier

The first graded index (GRIN) polymer waveguide amplifier working at 1.06 mu m wavelength has been realized, using a Nd/sup 3+/: photolime gel material combination. Throughput intensity of 3.8 mW at 1.06 mu m, corresponding to 8.5 dB gain, was observed when employing a 40 mW pumping laser beam operating at 790 nm. The gain medium is a 2.2 cm waveguide active region with Nd/sup 3+/ concentration of 1.03*10/sup 20//cm/sup 3/. The GRIN characteristic of the photolime gel thin film provides a universal means for implementing polymer-based photonic integrated circuits (PICs) on any substrate of interest.<<ETX>>

60 GHz board‐to‐board optical interconnection using polymer optical buses in conjunction with microprism couplers

We have demonstrated for the first time 60 GHz wide‐band board‐to‐board optical interconnection with a signal‐to‐noise ratio of 22 dB. The total interconnection distance is 55 cm from the input coupling prism to the detector. Board‐to‐board optical interconnection was realized using microprisms which had a measured coupling bandwidth of more than 250 nm. The graded index of the polymer waveguide allows us to implement such an interconnection scheme on an array of substrates. The elimination of backplane interconnection greatly enhances the interconnection speed. The implementation of a high‐speed on‐board transceiver in connection with a polymer waveguide lens will generate a fully on‐board optical interconnect involving modulation/demodulation.

Electro-optic and all-optical phase modulator on an indium tin oxide single-mode waveguide

We have successfully demonstrated an In2O3:Sn semiconductor thin‐film waveguide. The energy gap of the film can be manipulated from 3.1 eV (0.4 μm) to 3.7 eV (0.335 μm) by changing the ratio of In2O3 and SnO2. Waveguide propagation losses of 3 dB/cm for transverse magnetic (TM) and 8 dB/cm for transverse electric (TE) guided waves were experimentally confirmed at the wavelength of 632.8 nm. A phase modulator containing an indium tin oxide waveguide, two holographic mirrors, two microprisms, and two ohmic contacts were fabricated. Electro‐optic (current injection) and all‐optical modulations were conducted. A modulation depth of 18% was experimentally confirmed for the current injection device, using 15‐V applied voltage, and a modulation depth of 15% using 250 mW 355 nm UV light as the activation sources. An In2O3:Sn waveguide device working at the cutoff boundary was made. A modulation depth of 26 dB was measured with an applied voltage of 30 V. An array of applications, including use in current sensors,...

Highly multiplexed graded‐index polymer waveguide hologram for near‐infrared eight‐channel wavelength division demultiplexing

An eight‐channel single‐mode wavelength division demultiplexer operating at 740, 750, 760, 770, 780, 790, 800, and 810 nm with diffraction angle varying from 16° to 44° and using a graded index (GRIN) polymer waveguide is reported for the first time. Diffraction efficiency up to 55% was measured. The wavelength spreading of the Ti:Al2O3 laser (∼4 nm, 3 dB bandwidth) causes an average crosstalk figure of −15.8 dB. The beamwidth of the diffracted signal as a function of the input beamwidth, the grating interaction length, and the diffraction angle are considered. Occurrence of the maximum value is further discussed. A waveguide lens is needed to efficiently couple the diffracted light into an output fiber whenever the diffracted beam size is beyond the core diameter of the fiber involved.

Reconfigurable optical interconnection network for multimode optical fiber sensor arrays

A single-source, single-detector architecture has been developed to implement a reconfigurable optical interconnection network for multimode optical fiber sensor arrays. The network was realized by integrating LiNbO 3 electro-optic (EO) gratings working at the Raman Nath regime and a massive fan-out waveguide hologram (WH) working at the Bragg regime onto a multimode glass waveguide. The glass waveguide utilized the whole substrate as a guiding medium. A 1-to-59 massive waveguide fan-out was demonstrated using a WH operating at 514 nm. Measured diffraction efficiency of 59% was experimentally confirmed. Reconfigurability of the interconnection was carried out by generating an EO grating through an externally applied electric field. Unlike conventional single-mode integrated optical devices, the guided mode demonstrated here has an azimuthal symmetry in mode profile which is the same as that of a fiber mode.

Large-area waveguide sensor for multiple analytes detection

A highly sensitive fluoroimmunoassay optical waveguide for the monitoring of biological agents was developed. The scope and versatility of this method was enhanced by combining the principle of fluoroimmunoassay with latex-based waveguide evanescent wave sensing technology. A novel waveguide probe was successfully demonstrated as an antibody-based biosensor. Based on a designed biological model, human immunoglobulin G (h-IgG) were sensitively (0.3 ng/ml, 2 X 10-12 M) and rapidly (2 minutes assay time) identified and quantified using a diode laser (635 nm). The latex-based thin film has excellent optical quality and an established immunochemistry, making it stable and reliable for sensing applications. Because polymer-matrix waveguide is inexpensive and disposable, the probe cartridge is suitable for one time assay. Very fast and highly sensitive biosensors are potentially useful for many medical and clinical diagnostics, especially for intensive or emergency care patients.

Indium tin oxide single-mode waveguide modulator

We have successfully demonstrated an In203:Sn semiconductor thin film waveguide. The energy gap of the film can be manipulated from 3.1 eV (0.4 pm) to 3.7 eV (0.335 mm) by changing the ratio of In203 and Sn02. Waveguide propagation losses of 3 dB/cm for transverse magnetic (TM) and 8 dB/cm for transverse electric (TE) guided waves were experimentally confirmed at the wavelength of 632.8 mm. A phase modulator containing an indium tin oxide waveguide, two holographic mirrors, two microprisms, and two ohmic contacts was fabricated. Electro-optic (current injection) and all optical modulations were conducted. A modulation depth of 18% was experimentally confirmed for the current injection device, using 15-volt applied voltage, and a modulation depth of 15% using 250 mW 355 nm UV light as the activation sources. An In203:Sn waveguide device working at the cutoff boundary was made. A modulation depth of 26 dB was measured with an applied voltage of 30 volts. An array of applications, including use in current sensors, ozone UV sensors, attenuated total reflection (ATR) modulators, delay lines for phased array antennae and multi-quantum wells are highly feasible.

Single‐mode optically activated phase modulator on GaAs/GaAlAs compound semiconductor rib waveguides

We report on an optically activated phase modulator (OAM) and modulator array on GaAs‐GaAlAs compound semiconductor rib waveguides. A rib waveguide device with an optical activation window of 5 μm in diameter was fabricated. Optical activation was produced by using a HeNe 632.8 nm wavelength as the free‐carrier generator and a 1.3 μm laser as the signal carrier. A 33% modulation depth was observed and 10−2 index modulation was experimentally confirmed on an OAM working in the phase modulation regime. OAMs working in both phase‐ and cutoff‐modulation regimes were further determined by considering the variation of the waveguide confinement factor. An 8.2 dB modulation depth was observed on an OAM working at the cutoff regime. Furthermore, the activation source for the free‐carrier generation is in the mW power region, which significantly reduces the size and cost of all optical switching devices.

Ten-channel single-mode wavelength division demultiplexer in near IR

A ten-channel single-mode wavelength division demultiplexer operating at 740, 750, 760, 770, 780, 790,800,810,820 and 830 nm with diffraction angles varying from 16° to 52° and using a graded index (GRIN) polymer waveguide is reported for the first time. Diffraction efficiency up to 60% was measured. The wavelength spreading of the Ti:Al2O3 laser (~ 4 nm, 3 dB bandwidth) causes an average crosstalk figure of -21 dB. The beamwidth of the diffracted signal as a function of the input beam width, the grating interaction length, and the diffraction angle are considered. Occurrence of maximum values are discussed. A waveguide lens is needed to efficiently couple the diffracted light into an output fiber whenever the diffracted beam size is beyond the core diameter of the fiber involved.