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Lasers and Electro-Optics Society Annual Meeting, 1994. LEOS '94 Conference Proceedings. IEEE

Date Oct. 31 1994-Nov. 3 1994

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  • Leos '94 Conference Proceedings Volume 2 [front matter]

    Publication Year: 1994 , Page(s): i - ix
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    Freely Available from IEEE
  • Author index

    Publication Year: 1994 , Page(s): 446 - 449
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    Freely Available from IEEE
  • High-density integrated 1×16 optical FDM multi/demultiplexer

    Publication Year: 1994 , Page(s): 263 - 264 vol.2
    Cited by:  Papers (2)
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    Integrated optical multi/demultiplexers based on Mach-Zehnder (MZ) interferometers are promising devices for optical frequency division multiplexing (FDM) transmission systems. 1×4 and 1×8 optical FDM multi/demultiplexers have been fabricated using planar lightwave circuit (PLC) technology based on silica-glass waveguides on Si. In order to realize higher density integrated multi/demultiplexer that are larger in scale, it will be advantageous to use waveguides with a high relative refractive index difference (high-Δ) because of their small bending radius. This paper presents a high-density integrated 1×16 optical FDM multi/demultiplexer using high-Δ silica-glass waveguides, which is larger in scale than any previously reported optical multi/demultiplexer based on MZ interferometers View full abstract»

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  • Studies on carrier confinement for polymer electroluminescent devices with multilayer structure

    Publication Year: 1994 , Page(s): 357 - 358 vol.2
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    Recently, high luminance and high efficiency were realized in organic thin-film electroluminescence devices with multilayer structure, which include an emitting layer, a hole transporting layer, and an electron transporting layer. Generally these carrier transporting layers have the properties of inhibiting different type carriers such as transporting hole while inhibition electrons, by which the carrier are confinement in emitting layer. In this letter, we report some properties of hole blocking layers which were realized in a double layer structure with ITO/emitting layer/hole blocking layer/Al. In this structure, the emitting layer was 1,1,4,4,-tetraphenyl-1,3-butadiene(TPB) doped poly(N-vinylcarbazole) (PVK), which has large hole mobility, and hole blocking layer was PBD View full abstract»

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  • Novel wavelength router with coupling through a semiconductor vertical cavity

    Publication Year: 1994 , Page(s): 265 - 266 vol.2
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    We have demonstrated a novel AlGaAs-AlAs QW structure where the transfer of optical power between two waveguides occurs through a semiconductor cavity and the transfer position depends on wavelength. Such a structure may be configured to provide wavelength dependent gain or absorption for WDM applications View full abstract»

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  • Angled-facet high-power diffraction-limited tapered semiconductor amplifier

    Publication Year: 1994 , Page(s): 399 - 400 vol.2
    Cited by:  Patents (1)
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    Summary form only given. Tapered semiconductor amplifiers have successfully demonstrated high-power diffraction-limited emission. So far, all these amplifiers had normal incidence facets coated with antireflection (AR) coating to prevent self-oscillation. In this work, an angled-facet high-power diffraction-limited tapered GaAs-AlGaAs QW semiconductor amplifier operating at 809-nm was realized. Due to the angled facet structure, any residual reflection from the facets is fed back at a small angle with the signal propagation direction View full abstract»

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  • Low-loss fiber-to-semiconductor waveguide coupling using integrated optical mode expanders

    Publication Year: 1994 , Page(s): 267 - 268 vol.2
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    In this paper we report improved optical mode expanders resulting in coupling losses of below 1 dB and relaxed alignment tolerances of 2.5 μm in the horizontal and vertical directions for 1 dB in addition measured with standard single mode fiber (SMF). In a first fabrication step the OEIC waveguide components are grown by low-pressure metal-organic vapor-phase epitaxy. An oxide mask is deposited and patterned with narrowing mask openings in the optical mode expanders View full abstract»

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  • Upconversion studies in Tm, Ho co-doped alumino-zirco-fluoride glass

    Publication Year: 1994 , Page(s): 427 - 428 vol.2
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    Tm, Ho co-doped alumino-zirco-fluoride (AZF) glass is an attractive candidate for an optical pre-amplifier around two microns. In Tm, Ho doped materials, however, upconversion from the upper laser levels of Tm 3F4 and Ho 5I7 occurs which reduces the gain coefficient and efficiency. Therefore it is important to determine the upconversion rate constants in order to estimate optimum performance of such a Tm, Ho: AZF glass pre-amplifier. In this work, the upconversion rate constants were determined under high average power pumping conditions by measuring gain coefficients and an appropriate comparison made from a simple rate equation model View full abstract»

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  • Multiplexed Bragg grating fiber sensors

    Publication Year: 1994 , Page(s): 153 - 154 vol.2
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (196 KB)  

    By combining wavelength and time division multiplexing the number of sensors which could potentially be addressed increases to the tens to possibly one hundred devices, depending on the strain resolution and measurement bandwidths required. Recently developed fiber draw-tower fabrication techniques should allow the production of such fibre Bragg grating (FBG) arrays at low cost. FBG based sensors thus represent a powerful enabling technology for use in a wide range of structural sensing applications View full abstract»

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  • Self-action of ultrashort intense laser pulses in dense gases: self-focusing, optical breakdown, supercontinuum generation

    Publication Year: 1994 , Page(s): 97 - 98 vol.2
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    Self-action during the propagation of ultrashort intense laser pulses through dense gases is practically unavoidable and leads to a dramatic change of pulse characteristics such as the beam size and frequency spectrum. The authors report results of experiments on propagation of ultrashort intense laser pulses in high pressure (1-40 atm) gas media. Self-focusing (SF) was observed under various conditions of gas pressure and laser power, accompanied by such phenomena as supercontinuum (SC) generation, conical emission (CE) and optical breakdown (OB). Supercontinuum generation (i.e. a nearly white spectrum generated upon propagation of intense short laser pulses through nonlinear media) has been observed in gases only recently, with appearance a new generation of powerful ultrashort lasers. The authors measured for the first time the spectral evolution of the supercontinuum radiation as a function of incident laser power and gas pressure. The single shot SC spectrum was deeply modulated, with this modulation changing with gas pressure and laser power. Beyond the SC generation threshold the authors also observed an intense conical emission with sharp spectral and spatial maxima View full abstract»

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  • Solid source MBE growth of lattice matched GaInAsP with phosphorus and arsenic valved cracking cells

    Publication Year: 1994
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    Summary form only given. Reproducible As/P stoichiometric growth was obtained with all solid source MBE. Valved cells containing in-situ generated white phosphorus and arsenic were employed to achieve high optical quality GaInAsP layers on InP and GaAs. Laser diode performance will also be discussed View full abstract»

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  • Nonlinear optical and electro-optical characteristics of hybrid AlAs/GaAs multilayered structures

    Publication Year: 1994 , Page(s): 336 - 337 vol.2
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    In this paper, experimental results on giant electro-optical nonlinearities in a periodic multilayered structure are presented. The device consists of undoped GaAs and AlAs layers with nominal thicknesses of 58 nm and 69 nm, respectively. In summary, it is shown that hybrid multilayered semiconductor structures exhibit clear electro-optical modulation and giant optical nonlinearities leading to optical bistabilities at extremely low optical intensities. Thus, such devices offer potential applications for parallel signal processing View full abstract»

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  • Smart lasers for medical laser treatments

    Publication Year: 1994 , Page(s): 69 - 70 vol.2
    Cited by:  Patents (1)
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    Summary form only given. There have in recent years been increasing efforts to incorporate intelligent feedback control systems into lasers used for medical treatments. The goal has been to achieve more selective energy delivery to targeted vs healthy tissue and more precise control of laser dosimetry. Achieving these goals should lead to better patient outcomes, as well as easier and/or faster treatments. A feedback control system for a medical treatment laser generally consists of four principal components: (1) a sensor which monitors tissue response to the treatment laser (or to an auxiliary excitation source), (2) signal conditioning/processing hardware which processes the signal to a useful format, (3) an analysis algorithm which interprets the processed data to assess tissue type or tissue state, e.g., temperature, induced stress, etc., and (4) an active beam control device which controls beam energy delivery in a responsive way View full abstract»

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  • Lasing properties of GaAs/AlGaAs lasers grown by MOVPE and bandgap-shifted by impurity free vacancy diffusion

    Publication Year: 1994 , Page(s): 375 - 376 vol.2
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    Bandgap shifting by impurity-free vacancy diffusion was investigated using carbon p-doped quantum well laser structures. Spectra and L-I characteristics were measured and compared with as-grown material confirming that high lasing efficiency was maintained View full abstract»

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  • Unique aspects of waveguide diode ring lasers

    Publication Year: 1994 , Page(s): 393 - 394 vol.2
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    In this paper, we present a combination of significant new experimental results on the operating characteristics of the triangular ring diode lasers we fabricated, which exhibit the unique aspects of these lasers and confirm the fundamental properties and limitations predicted by recent theoretical analysis View full abstract»

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  • 1.55 μm dual polarization lasers containing tensile and compressive strained quantum wells

    Publication Year: 1994 , Page(s): 383 - 384 vol.2
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    We have demonstrated lasing in two polarizations in a InP-InGaAsP strained quantum well laser at 1.55 μm and have been able to switch the lasing polarization with change in temperature. The analysis of the lasing behavior of this device aids in the design of polarization insensitive amplifiers and dual polarization-lasers as well as offers insight into the process of carrier capture and leakage in quantum wells View full abstract»

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  • Comparison of self-pulsation mechanisms in DFB laser diodes

    Publication Year: 1994 , Page(s): 167 - 168 vol.2
    Cited by:  Papers (1)
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    Split-contact DFB lasers are shown, through large signal dynamic modelling, to self-pulsate at multi-gigabit frequencies. Two different mechanisms are identified and discussed for clock-recovery applications: multimode pulsations involving mode switching, and a faster, single-moded kind View full abstract»

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  • Bragg reflection filter wavemeter for the writing of multiple transverse holographic optical fiber gratings

    Publication Year: 1994 , Page(s): 155 - 156 vol.2
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    A new device, establishing a wavelength standard for precise modulation spacing of transverse holographic gratings, is reported. Each writing location and wavelength is calibrated against a known laser standard, allowing a precision approaching one part in one million View full abstract»

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  • Gigabit networking research

    Publication Year: 1994 , Page(s): 367 - 368 vol.2
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    Two approaches to achieving transmission capacities of 20 Gbit/s that are currently being supported in various network testbeds are a) expanding the SONET/SDH transmission hierarchy to the OC-192 (9.953 Gb/s) data rate and b) using wavelength division multiplexing techniques. The former approach offers the potential to upgrade existing optical fiber facilities and to use transmission protocols and operations procedures that are already familiar to the data communications community. One of the most significant advantages to OC-192 systems is the potential to reduce network implementation and operations costs View full abstract»

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  • A robust WDM communication system

    Publication Year: 1994 , Page(s): 99 - 100 vol.2
    Cited by:  Papers (7)  |  Patents (1)
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    An architecture is described which accommodates the difficult physical constraints in a WDM optical network, especially the inevitable wavelength drifts many times the source linewidths, by using an adaptive receiver system. The equally difficult and conflicting requirements of a multi-media, multi-Gb/s network of fixed and low latency, guaranteed bandwidth, and multi-cast have also been met by adapting the DTM protocol to mixed WDM and TDM optical formats View full abstract»

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  • Recent advances of in-situ process in molecular beam epitaxy

    Publication Year: 1994
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    Summary form only given. In-situ process combines film growth and device fabrication steps which take place under an ultra high vacuum or a controlled ambient environment. Results of materials and devices produced using this technique with molecular beam epitaxy are reviewed View full abstract»

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  • Multi-wavelength multi-Gbit/sec dispersion compensated transmission system

    Publication Year: 1994 , Page(s): 101 - 102 vol.2
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    This paper presents experimental results of simultaneous dispersion-compensation of multi-wavelength 1550 nm WDM signals (within erbium-doped optical fiber amplifier bandwidth), for transmission in conventional 1310 nn-optimized single-mode fibers taking advantage of chirped pulse transmission View full abstract»

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  • Nonlinear optics and electroluminescence using high vacuum deposited organic thin films

    Publication Year: 1994
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    Summary form only given. We discuss recent developments in the demonstration and understanding of nonlinear optical and electroluminescence effects in very thin, ordered organic films grown via organic molecular beam deposition. Applications to photonic switching and displays will be discussed View full abstract»

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  • Dense WDM with femtosecond laser pulses

    Publication Year: 1994 , Page(s): 199 - 200 vol.2
    Cited by:  Papers (1)  |  Patents (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (192 KB)  

    We present an application of femtosecond laser pulses that is not directly related to high speed, but rather makes use of the large spectral bandwidth of these pulses to address a systems issue in wavelength-division-multiplexed (WDM) communication links. One inherent difficulty of currently proposed WDM systems is the need for multiple lasers operating at different wavelengths, which hence have to be wavelength-selected and stabilized at that particular wavelength for years to come. We demonstrate a WDM system based on a single short-pulse laser source that covers all WDM channels simultaneously, hence eliminating many of the source problems of conventional WDM systems View full abstract»

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  • Reconfigurable all-optical network design, integration and demonstration

    Publication Year: 1994
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    Summary form only given. We present here for the first time the system demonstration of a network testbed that comprises of a four-node, two-ring and five WDM X-Cs, and four ATM/SONET switches to perform reconfigurable user-requested multimedia services. The objective here is to study the characteristics of rearrangeability and control algorithms through wavelength re-use and wavelength translation in a network testbed View full abstract»

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