Abstract: A scanning optical monitoring system and method are appropriate for high speed scanning of a WDM signal band. The system and method are able to identify dropped channels or, more generally, discrepancies between the determined or detected channel inventory and a perpetual inventory for the WDM signal, which perpetual inventory specifies the channels that should be present in the WDM signal assuming proper operation of the network. The system includes a tunable optical filter that scans a pass band across a signal band of a WDM signal to generate a filtered signal. A photodetector then generates an electrical signal in response to this filtered signal. A decision circuit compares the electrical signal to a threshold and a controller, which is responsive to the decision circuit, inventories the channels in the WDM signal.

Abstract: Integrated spectroscopy systems are disclosed. In some examples, integrated tunable detectors, using one or multiple Fabry-Perot tunable filters, are provided. Other examples use integrated tunable sources. The tunable source combines one or multiple diodes, such as superluminescent light emitting diodes (SLED), and a Fabry Perot tunable filter or etalon. The advantages associated with the use of the tunable etalon are that it can be small, relatively low power consumption device. For example, newer microelectrical mechanical system (MEMS) implementations of these devices make them the size of a chip. This increases their robustness and also their performance. In some examples, an isolator, amplifier, and/or reference system is further provided integrated.

Abstract: A scanning optical monitoring system and method are appropriate for high speed scanning of a WDM signal band. The system and method are able to identify dropped channels or, more generally, discrepancies between the determined or detected channel inventory and a perpetual inventory for the WDM signal, which perpetual inventory specifies the channels that should be present in the WDM signal assuming proper operation of the network. The system includes a tunable optical filter that scans a pass band across a signal band of a WDM signal to generate a filtered signal. A photodetector then generates an electrical signal in response to this filtered signal. A decision circuit compares the electrical signal to a threshold and a controller, which is responsive to the decision circuit, inventories the channels in the WDM signal.

Abstract: A spectroscopy system comprises a tunable semiconductor laser, such as an external cavity laser, that generates a tunable signal. A detector is provided for detecting the tunable signal after interaction with a sample. In this way, the system is able to determine the spectroscopic response of the sample by tuning the laser of the scan band and monitoring the detector's response. An integrating device, such as an integrating sphere, is interposed optically between the tunable semiconductor laser and the detector. This integrating device is used to mitigate the effects of parasitic spectral noise, such as noise that is generated by speckle or the combination of single- and multi-mode optical fibers in the transmission link between the tunable semiconductor laser and the detector.

Abstract: Integrated spectroscopy systems are disclosed. In some examples, integrated tunable detectors, using one or multiple Fabry-Perot tunable filters, are provided. Other examples use integrated tunable sources. The tunable source combines one or multiple diodes, such as superluminescent light emitting diodes (SLED), and a Fabry Perot tunable filter or etalon. The advantages associated with the use of the tunable etalon are that it can be small, relatively low power consumption device. For example, newer microelectrical mechanical system (MEMS) implementations of these devices make them the size of a chip. This increases their robustness and also their performance. In some examples, an isolator, amplifier, and/or reference system is further provided integrated.

Abstract: A semiconductor source spectroscopy system controls optical power variation of the tunable signal due to polarization dependent loss in the system and thus improves the noise performance of the system. It relies on using polarization control between the source and the sample and/or the sample and the detector.

Abstract: Integrated spectroscopy systems are disclosed. In some examples, integrated tunable detectors, using one or multiple Fabry-Perot tunable filters, are provided. Other examples use integrated tunable sources. The tunable source combines one or multiple diodes, such as superluminescent light emitting diodes (SLED), and a Fabry Perot tunable filter or etalon. The advantages associated with the use of the tunable etalon are that it can be small, relatively low power consumption device. For example, newer microelectrical mechanical system (MEMS) implementations of these devices make them the size of a chip. This increases their robustness and also their performance. In some examples, an isolator, amplifier, and/or reference system is further provided integrated.

Abstract: A multi semiconductor source tunable spectroscopy system has two or more semiconductor sources for generating tunable optical signals that are tunable over different spectral bands. The system enables the combination of these tunable signals to form an output signal that is tunable over a combined band including these individual spectral bands of the separate semiconductor sources. The system further compensates for spectral roll-off associated with the semiconductor sources. Specifically, near the limits of the semiconductor sources' spectral bands, the power in the tunable signal tends to degrade or decrease. The system compensates for this roll-off using drive current control, attenuators, or electronic compensation.

Abstract: An optical power control system for a semiconductor source spectroscopy system controls power fluctuations in the tunable signal from the spectroscopy system and thus improves the noise performance of the system. This general solution has advantages relative to other systems that simply detect reference power levels during the scan and then correct the detected signal after interaction with the sample by reducing the requirements for coordinating the operation of the sample detectors and power or reference detectors. The spectroscopy system comprises a semiconductor source and a tunable filter. The combination of the semiconductor source and tunable signal illuminate a sample with a tunable signal, being tunable over a scan band. The power control system comprises an amplitude detector system for detecting the power of the tunable optical signal and power control system for regulating the amplitude of the tunable optical signal in response to its detected power.

Abstract: An optical power control system for a semiconductor source spectroscopy system controls power fluctuations in the tunable signal from the spectroscopy system and thus improves the noise performance of the system. This general solution has advantages relative to other systems that simply detect reference power levels during the scan and then correct the detected signal after interaction with the sample by reducing the requirements for coordinating the operation of the sample detectors and power or reference detectors. The spectroscopy system comprises a semiconductor source and a tunable filter. The combination of the semiconductor source and tunable signal illuminate a sample with a tunable signal, being tunable over a scan band. The power control system comprises an amplitude detector system for detecting the power of the tunable optical signal and power control system for regulating the amplitude of the tunable optical signal in response to its detected power.

Abstract: An optical power control system for a semiconductor source spectroscopy system controls power fluctuations in the tunable signal from the spectroscopy system and thus improves the noise performance of the system. This general solution has advantages relative to other systems that simply detect reference power levels during the scan and then correct the detected signal after interaction with the sample by reducing the requirements for coordinating the operation of the sample detectors and power or reference detectors. The spectroscopy system comprises a semiconductor source and a tunable filter. The combination of the semiconductor source and tunable signal illuminate a sample with a tunable signal, being tunable over a scan band. The power control system comprises an amplitude detector system for detecting the power of the tunable optical signal and power control system for regulating the amplitude of the tunable optical signal in response to its detected power.

Abstract: Integrated spectroscopy systems are disclosed. In some examples, integrated tunable detectors, using one or multiple Fabry-Perot tunable filters, are provided. Other examples use integrated tunable sources. The tunable source combines one or multiple diodes, such as superluminescent light emitting diodes (SLED), and a Fabry Perot tunable filter or etalon. The advantages associated with the use of the tunable etalon are that it can be small, relatively low power consumption device. For example, newer microelectrical mechanical system (MEMS) implementations of these devices make them the size of a chip. This increases their robustness and also their performance. In some examples, an isolator, amplifier, and/or reference system is further provided integrated.

Abstract: In a MOEMS device and corresponding fabrication process, absorbing material along the optical axis of the device is removed. The result is a suspended optical coating, such as a dielectric thin film mirror stack. Such optical coatings can have very low absorption. Thus, the invention can materially lower the net absorption in the device, and thereby improve performance, by degrading power related dependencies.

Abstract: A process for tunable filter train alignment comprises detecting a spectral response of the filter train and aligning an optical fiber that transmits an input optical signal to the filter train during operation. Further, the tunable filter is moved relative to the filter train in response to a spectral response of the filter train. As a result, the alignment and spectral response of the tunable filter train are optimized. In the preferred embodiment, the alignment and SMSR optimization occur simultaneously with respect to each other.

Abstract: A detector system for a fiber optic component is insensitive to stray light. Specifically, the invention comprises a detector chip, which converts received light into an electric signal. A baffle substrate is positioned over the detector chip. This baffle substrate has a transmission port through which an optical signal is transmitted to the detector chip. As a result, light that is not directed to be transmitted through the port is blocked by the baffle substrate. In this way, it rejects stray light that may be present in the hermetic package. A detector substrate is provided on which the detector chip is mounted. This detector substrate preferably comprises electrical traces to which the detector chip is electrically connected. The detector substrate can further comprise bond pads for wire bonding to make electrical connections to the electrical traces.

Abstract: A MOEMS Fabry-Perot tunable filter includes an optical membrane structure. Two electrostatic cavities are provided, one on either side of the membrane structure. As a result, electrostatic attractive forces can be exerted on the optical membrane to enable deflection in either direction, typically, along the optical axis. This is useful in calibrating the tunable filter during operation to an initial wavelength (&lgr;o) set point. It is also useful in controlling the membrane to avoid unstable operation.

Abstract: One problem that arises in the context of controlling tunable filters, and more specifically, Fabry-Perot tunable filters concerns the control algorithms for these MOEMS devices. An optical filter system comprises a tunable optical filter that scans a pass band across a signal band to generate a filtered signal. A filter tuning voltage generator generates a tuning voltage to the optical tunable filter. A photodetector generates an electrical signal in response to the filtered signal. Finally, a controller, that is responsive to the photodetector, triggers the filter tuning voltage generator. To increase the ease at which the results of a scan of the signal band of a WDM signal can be analyzed and improve spectral resolution, the change in the pass band of the tunable filter as a function of time is linearized in frequency or wavelength. This is achieved through the use of essentially an arbitrary waveform generator as the filter tuning voltage generator.

Abstract: A process for tunable filter train alignment comprises detecting a spectral response of the filter train and aligning an optical fiber that transmits an input optical signal to the filter train during operation. Further, the tunable filter is moved relative to the filter train in response to a spectral response of the filter train. As a result, the alignment and spectral response of the tunable filter train are optimized. In the preferred embodiment, the alignment and SMSR optimization occur simultaneously with respect to each other.

Abstract: A method of forming a fiber probe having an aperture for use in near-field scanning optical microscopy. The method includes a first steps of coating an optical fiber having a tapered tip with a metal layer. Next is a step of milling the tapered tip and metal layer such that an aperture is formed through the metal layer at the tapered tip. The milling step includes focused ion-beam milling the tapered tip and metal layer. The focused ion-beam milling can be done by raster scanning the focused ion-beam in a rectangular pattern at an apex of the tapered tip. Also, the fiber probe made through the above outlined method is used in near-field scanning optical microscopy.

Abstract: A process for tunable filter train alignment comprises detecting a spectral response of the filter train and aligning an optical fiber that transmits an input optical signal to the filter train during operation. Further, the tunable filter is moved relative to the filter train in response to a spectral response of the filter train. As a result, the alignment and spectral response of the tunable filter train are optimized. In the preferred embodiment, the alignment and SMSR optimization occur simultaneously with respect to each other.