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 laser system for a spectroscopic catheter system uses multiple semiconductor gain media having gain peaks at different wavelengths. The output from the gain media is preferably coupled into single-mode fiber using conventional opto-electronic packaging techniques. As a result, the laser oscillator source has a spectral output that is wider than the gain bandwidth of a single medium to enable it to access the entire spectrum of interest, which is presently in the near infrared. Moreover, the semiconductor gain media can be packaged in a stable and controlled environment for long-term performance.

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 tunable optical filter system 10 has a reference source system 24 that is integrated with the tunable filter 22 on bench 14 and within hermetic package 12. The reference source system 24 is temporally modulated to decrease interference or crosstalk into the scan of the optical signal 64 of interest. Specifically, a system controller 100 energizes the reference source during a reference scan in which the tunable filter 22 is scanned across a spectrum of the optical reference 66. The controller 100, however, lowers, such as simply decreasing or entirely cutting, power to the reference source system 24 during a signal scan, in which the tunable filter 22 is scanned across the optical signal's spectrum. In this way, interference during the signal scan from the reference source system is reduced.

Abstract: A tunable optical filter system 10 has a reference source system 24 that is integrated with the tunable filter 22 on bench 14 and within hermetic package 12. The reference source system 24 is temporally modulated to decrease interference or crosstalk into the scan of the optical signal 64 of interest. Specifically, a system controller 100 energizes the reference source during a reference scan in which the tunable filter 22 is scanned across a spectrum of the optical reference 66. The controller 100, however, lowers, such as simply decreasing or entirely cutting, power to the reference source system 24 during a signal scan, in which the tunable filter 22 is scanned across the optical signal's spectrum. In this way, interference during the signal scan from the reference source system is reduced.

Abstract: In optoelectronic systems, package moisture can affect stress levels in dielectric coatings on MEMS devices. Specifically, as the moisture content in these dielectric coatings changes, there are concomitant changes in the material stress. These changes in material stress can affect the operation of the overall MEMS device. Specifically, in the context of tunable filters, moisture can lead to a drift in the size of the optical resonant cavity over time as changes in material stress affect the MEMS structures. According to the invention, a getter is added to the package to absorb moisture, and thereby stabilize the operation of the optical filter, and specifically prevent uncontrolled drift in the size of its optical cavity.

Abstract: A tunable filter system comprises a signal source providing a WDM signal having multiple channels within a spectral signal band. A reference source generates a reference signal with spectral reference features that are typically located in a spectral reference band that is outside the signal band. A tunable filter is provided comprising a cavity bounded by at least two reflectors; at least one of these reflectors is a deflecting membrane to thereby create a tunable spectral pass band. The filter has a free spectral range that is greater than a combined bandwidth of the signal band and the reference band. The tunable filter pass band filters the reference signal and the WDM signal.

Abstract: A process for configuring a tunable MOEMS filter train comprises determining a spectral response of a MOEMS tunable filter. A spectral separation between different order modes, or free spectral range, is then determined for the filter. This information is then related to a mode size of a desired mode of the tunable filter. With this information, lenses for the optical train are provisioned, and then installed so that light is launched into the optical filter at the desired mode size to thereby maximize the SMSR of the filter train.

Abstract: A process for configuring a tunable MOEMS filter train comprises determining a spectral response of a MOEMS tunable filter. A spectral separation between different order modes, or free spectral range, is then determined for the filter. This information is then related to a mode size of a desired mode of the tunable filter. With this information, lenses for the optical train are provisioned, and then installed so that light is launched into the optical filter at the desired mode size to thereby maximize the SMSR of the filter train.

Abstract: An improved system and method for automated fiber polishing overcomes the limitations of conventional systems and methods. In particular, the present invention provides for continuous determination of the quality of the polish during a polishing procedure. An optical signal is transmitted to a fiber tip, and any back-reflected signal is detected and monitored to determine polish quality. In this manner, automated polishing quality assurance is provided in real time.

Abstract: In accordance with a feature of the invention, a hierarchy of multi-digraph layers may be constructed on top of an input multi-digraph. Each layer represents a multi-digraph obtained from an equivalence relation defined on the edge set of the input multi-digraph. In accordance with a further feature of the invention, each subgraph is small enough to be represented visually in a variety of novel ways.

Abstract: A tunable filter system comprises a signal source providing a WDM signal having multiple channels within a spectral signal band. A reference source generates a reference signal with spectral reference features that are typically located in a spectral reference band that is outside the signal band. A tunable filter is provided comprising a cavity bounded by at least two reflectors; at least one of these reflectors is a deflecting membrane to thereby create a tunable spectral pass band. The filter has a free spectral range that is greater than a combined bandwidth of the signal band and the reference band. The tunable filter pass band filters the reference signal and the WDM signal.

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: An optical monitoring system provides for out-of-band calibration. As a result, calibration can be performed simultaneously with monitoring. This can be used to accomplish faster and/or more accurate scanning. In addition, the need for complex switching and/or multiplexing capabilities can be avoided. The system comprises a signal source of an optical signal having spectrally separated channels, which are distributed within a spectral band, such as a WDM signal. A reference source generates a reference signal outside of the spectral band. A tunable filter filters the optical signal and the reference signal. A reference signal detector then detects the filtered reference signal, while an optical signal detector detects the filtered optical signal.

Abstract: A semiconductor optical amplifier system comprises a hermetic package. In the typical implementation, this hermetic package is a standard 0.75 inch×0.5 inch package, such as a butterfly package. An optical bench is sealed within this package. A first fiber pigtail enters this package via a feed-through to connect to the bench and terminate above the bench. A second optical fiber pigtail enters the package via a second fiber feed-through to connect to the bench and similarly, terminate above the bench. A semiconductor amplifier chip is connected to the bench to provide amplification. Isolators are further incorporated along with a monitoring diode to yield a fully integrated system.

Abstract: A process for configuring a tunable MOEMS filter train comprises determining a spectral response of a MOEMS tunable filter. A spectral separation between different order modes, or free spectral range, is then determined for the filter. This information is then related to a mode size of a desired mode of the tunable filter. With this information, lenses for the optical train are provisioned, and then installed so that light is launched into the optical filter at the desired mode size to thereby maximize the SMSR of the filter train.

Abstract: It is an object of the invention to reduce the risk of misuse of a user's credit card number while avoiding having to securely contact and authenticate with a card-issuer before each transaction. In accordance with an aspect of the invention, the card-holder/user has access to a temporary authorization number generator, which is capable of accepting data from the user, such as the user's credit card number, and generating a cryptographically-secure temporary authorization number that is used in lieu of the user's credit card number in transactions. The card-issuer need not know the temporary authorization number before receiving the request for authorization from a merchant presented with it during a transaction. The present invention, while not limited to electronic commerce transactions, is especially suited for electronic commerce transactions occurring over a telecommunication network where the user cannot trust the integrity of either the network or the merchant receiving the credit card number.

Abstract: An improved fiber endface shape for increasing coupling of optical power from a source into fiber and its manufacture are disclosed. The inventive tip comprises a cleaved end surface that is preferably substantially orthogonal to the fiber's axis and a first and second polished, angled surfaces intersecting the end surface. Break-lines between the angled surfaces and the end surface fall near an edge of a cladding-core interface and preferably outside that interface when the fiber and transmitted light are such that a substantial portion of the light is transmitted in the cladding. A spatial intensity profile of light exiting from the tip is detected during manufacture and is used to monitor the polishing of the angled surfaces. Tests have shown that the inventive tip achieves the coupling efficiency associated with the double-angled wedge-shaped fiber tips while maintaining much of the ease of manufacture associated with the single-angle wedge tips.

Abstract: An improved fiber endface shape for increasing coupling of optical power from a source into fiber and its manufacture are disclosed. The inventive tip comprises a cleaved end surface that is preferably substantially orthogonal to the fiber's axis and a first and second polished, angled surfaces intersecting the end surface. Break-lines between the angled surfaces and the end surface fall near an edge of a cladding-core interface and preferably outside that interface when the fiber and transmitted light are such that a substantial portion of the light is transmitted in the cladding. A spatial intensity profile of light exiting from the tip is detected during manufacture and is used to monitor the polishing of the angled surfaces. Tests have shown that the inventive tip achieves the coupling efficiency associated with the double-angled wedge-shaped fiber tips while maintaining much of the ease of manufacture associated with the single-angle wedge tips.