Showing papers by "Barry Miller published in 1996"

Polarisation insensitive semiconductor optical amplifier with integrated electroabsorption modulators

Abstract: The authors demonstrate a 1.55 /spl mu/m wavelength multiquantum well semiconductor optical amplifier, integrated with bulk layer electroabsorption modulators and passive waveguide beam expanders at the input and output ports. The device has a fibre to fibre gain of 9 dB, an extinction ratio of 15 dB per modulator, a spectral range >35 nm, and polarisation sensitivity <1 dB.

Stimulated Brillouin scattering suppression with low residual AM using a novel temperature wavelength-dithered DFB laser diode

Abstract: The effective threshold for stimulated Brillouin scattering for a data-encoded signal is increased from 11.0 to 23.4 dBm by using a temperature-tunable laser diode. A 5 kHz sinusoid is applied to a Ti/Pt thin film resistor located along the laser contact on top of the device, resulting in a 10 kHz dithering of the wavelength. The residual amplitude modulation index at 10 kHz is only 1.2/spl times/10/sup -4/.

A Polarization Insensitive Semiconductor Optical Amplifier with Integrated Electroabsorption Modulators

Abstract: As optical access to the loop becomes more advanced, using emerging fiber to the loop (FTTL) architectures, and with the possible use of wavelength division multiplexing (WDM) to enhance transmission capacity and networking flexibility, it is important to consider new components that may be useful as building blocks for the upcoming local access networks. Obviously, for FTTL applications, low cost is an important prerequisite for components that are not widely shared. This may require uncooled operation, ease of packaging, and perhaps integration of opto-electronic devices. One of the new FTTL- WDM architectures that was recently demonstrated is RITE-Net [1,2], which is based on a WDM signals from a central office sent downstream to a remote node, and then to the local optical network unit (ONU). The carrier wavelength is modulated at the ONU using an on site optical modulator and returned upstream to the central office. One parameter that effects the performance is the insertion loss of the modulator. To improve the power budget of the system, it might be useful to employ a component that has integrated modulators and a semiconductor optical amplifier (SOA) resulting in a modest fiber to fiber gain rather than a large insertion loss. The proposed component can also enable WDM networks where frequency conversion and/or signal equalization over a large dynamic input range is required. It may be useful to integrate two modulators, so that one can be used for data encoding and the other for power level equalization.

A 1.3-μm wavelength laser with an integrated output power monitor using a directional coupler optical power tap

Abstract: A 1.3-/spl mu/m Fabry-Perot laser with a directional coupler power tap inside the laser cavity, used for diverting optical power to an integrated waveguide monitoring photodetector is demonstrated. The monitoring detector provides photocurrent which is linear with the front facet output power, with responsivity as high as 0.37 mA/mW, depending on the length of the directional coupler coupling region.

Four-wave mixing in semiconductor traveling-wave amplifiers for wavelength conversion in all-optical networks

Abstract: Intraband modulation in semiconductor gain media has recently been shown to provide a wideband nonlinearity which is five orders of magnitude larger than the Kerr non-linearity in silica fiber. We discuss recent work on the application of this nonlinearity to the wavelength conversion function in all optical networks; specifically, carrier wavelength spectral translation by four-wave mixing. In addition to reviewing the current performance of these devices including conversion efficiency, signal-to-noise and a simple system demonstration, we will describe the underlying physics of the ultra-fast four-wave mixing mechanism and its application to TeraHertz spectroscopy of intraband scattering. An overview of wavelength conversion in the context of all-optical networks is provided and competing techniques to four-wave mixing wavelength conversion are also discussed.

Low-chirp wavelength-selectable 1/spl times/6 laser arrays suitable for WDM applications

Abstract: Seven packaged wavelength selectable laser arrays were tested and found to have average chirp parameter of 018 /spl Aring/ under 25 Gb/Sec modulation Temperature tuning necessary to reach a standard WDM wavelength for any laser on any of the packages was /spl les/52/spl deg/C

SBS suppression using a temperature wavelength-modulated laser diode with low residual AM

Abstract: We report on an efficient method for suppressing stimulated Brillouin scattering (SBS) with negligible residual amplitude modulation (AM) using the temperature tunable properties of a semiconductor laser diode. We demonstrate an effective threshold of 23.4 dBm by applying a 16 V/sub pp/, 5 kHz sinusoid to a thin-film resistor on top of the laser diode. The residual AM is measured to be only 1.2/spl middot/10/sup -4/.

All-optical clock recovery from NRZ data using a nonlinear loop clock generator

Abstract: Summary form only given. In this paper, we demonstrate for the first time the feasibility of all-optical clock-recovery using NRZ pseudorandom data. To accomplish the clock-recovery function it is necessary to process the incoming data in two stages. First, a clock component is generated on the NRZ optical data stream and then this processed stream is used to injection lock a mode-locked fiber laser.

Low-chirp wavelength-selectable 1/spl times/6 laser arrays suitable for WDM applications

Abstract: Seven packaged wavelength selectable laser arrays were tested and found to have average chirp parameter of 0.18 /spl Aring/ under 2.5 Gb/Sec modulation. Temperature tuning necessary to reach a standard WDM wavelength for any laser on any of the packages was /spl les/5.2/spl deg/C.