Abstract: This invention provides an approach to lock the optical phase of a single sideband, carrier-suppressed coherent-AM analog optical link, so that for example an RF signal can be transmitted with high fidelity over fibers. In some embodiments, a method comprises providing a RF locking signal; impressing an RF input signal and the RF locking signal onto the optical field of a suppressed carrier; introducing the optical spectrum to a photonic integrated circuit comprising a microresonator filter and a finite impulse response filter; selectively passing the double sideband, associated with the locking frequency, through the finite impulse response filter; and recovering a RF output signal, wherein a feedback loop provides dithering to stabilize the optical phase of the link and thus preserve amplitude/phase integrity for the RF-photonic signal. The disclosed method is especially suited to the filtering of RF-photonic signals via use of the resonance passbands derived from microdisks or micro-rings.

Abstract: The present invention is a programmable and latching retro-reflective construct suitable for use as an optical label in an optical labeling system. The invention contains retro-reflective structures such as lens beads, corner cubes or other retro-reflecting type structures. The retro-reflective construct further comprises a wavelength selective, programmable and latching reflecting structure located at the reflecting surfaces of the retro-reflective structures. The optical construct can optionally contain additional optical filtering structures. Methods for fabricating the invention are also described.

Abstract: The present invention is a programmable and latching retro-reflective construct suitable for use as an optical label in an optical labeling system. The invention contains retro-reflective structures such as lens beads, corner cubes or other retro-reflecting type structures. The retro-reflective construct further comprises a wavelength selective, programmable and latching reflecting structure located at the reflecting surfaces of the retro-reflective structures. The optical construct can optionally contain additional optical filtering structures. Methods for fabricating the invention are also described.

Abstract: The present invention is a programmable and latching retro-reflective construct suitable for use as an optical label in an optical labeling system. The invention contains retro-reflective structures such as lens beads, corner cubes or other retro-reflecting type structures. The retro-reflective construct further comprises a wavelength selective, programmable and latching reflecting structure located at the reflecting surfaces of the retro-reflective structures. The optical construct can optionally contain additional optical filtering structures. Methods for fabricating the invention are also described.

Abstract: A laser transmitter with a feedback control loop for minimizing noise. The novel laser transmitter includes a laser, an external reflector adapted to form an extended cavity to the laser, and a feedback control loop adapted to detect noise in the laser and in accordance therewith, adjust the optical phase of the extended cavity such that the noise is at a desired level. The optical phase of the extended cavity is adjusted by adjusting an operating parameter of the laser, such as its bias current. In an illustrative embodiment, the feedback control loop is adapted to compute the rate of change of the noise with respect to bias current and in accordance therewith, adjust the bias current of the laser such that relative intensity noise and interferometric intermodulation distortion are simultaneously minimized.

Abstract: An optoelectronic-RF device has at least one optical modulator/sensor comprising at least two cascaded optical-waveguide gratings and at least one non-grating optical waveguide segment interconnecting the at least two cascaded optical-waveguide gratings, with at least one optical waveguide segment interconnecting the at least two cascaded optical-waveguide gratings via the at least one non-grating optical waveguide segment. An RF waveguide is provided for propagating an RF electric field, the at least one optical modulator/sensor being disposed in and forming a portion of the RF waveguide with light propagating through the cascaded optical-waveguide gratings in a direction that is perpendicular to a direction of propagation of the RF electric field in the RF waveguide.

Abstract: A method for minimizing the generation of interferometric intermodulation distortion in an analog fiber optic link that employs a directly modulated diode laser as its optical source. This is accomplished via the reduction of frequency chirp in the current-modulated diode laser source (32). To reduce frequency chirp, the diode laser (32) is coupled to an external reflector (52), so that an external laser cavity with a long, passive section is formed. Specifically, the frequency chirp of this extended laser cavity is reduced from that of the original diode laser by the ratio of the optical path length in the external cavity to that in the diode. The external reflector (52) can also be integrated, via splicing, to the fiber pigtail (54) of the laser transmitter (50) so that the compact geometric form factor of a diode transmitter is preserved.

Abstract: A method and apparatus for generating microwave signal frequencies. An incident reference signal is provided. A first stimulus signal is also provided, the first stimulus signal having a first polarization and having a first predetermined relationship with the incident reference signal. A second stimulus signal is also provided, the second stimulus signal having a second polarization and having a second predetermined relationship with the incident reference signal. The incident reference signal is split into a first polarization reference signal and into a second polarization reference signal. The first stimulus signal is coupled with the first polarization reference signal to provide first polarization mixed signals. The second stimulus signal is coupled with the second polarization reference signal to provide second polarization mixed signals.

Abstract: A method of forming a tapered optical waveguide within a substrate (2). An appropriate substrate (2) is coated with a layer of barrier material (4) such as silicon dioxide which provides a relatively tight matrix relative to the open matrix of the substrate (2). The barrier material (4) is deposited on the substrate with a sloping variable thickness that is inversely related to the desired depth of the waveguide taper. The barrier material (4) can be deposited through a vacuum deposition technique and subsequently subjected to ion-milling to provide the desired taper. An appropriate source of metal ions (6), such as silver, capable of being transferred, such as by diffusion into the substrate (2) for increasing the refractive index and thereby defining a waveguide, is then transmitted to and through the barrier material (4).

Abstract: There is disclosed a class of integrated optics devices comprising a variety of optical elements such as waveguides, lenses, couplers and the like, and a method of fabrication thereof. In particular, there is disclosed an aberration-free geodesic lens for integrated optics devices. In these devices, photo-induced refractive index changes in chalcogenide glass films may be used to fabricate a radial index of refraction distribution profile in order to form a lens. By varying the exposure of the thin film to ultra-violet light, variable index of refraction profiles may be formed. The variable profile may itself form the lens or, preferably, a thin film may be deposited on an aspherical geodesic lens in order to provide correction of focal length, thus reducing the mechanical tolerances required in the grinding process. These devices thus permit a degree of freedom heretofore unobtained in thin film optical waveguides for use in such devices as a spectrum analyzer operating at the 0.9 to 1.

Abstract: A multi-mode optical fiber is used to detect electrical currents or magnetic fields from a remote source. The optical fiber, which serves as the sensor, is composited with metal capable of conducting electricity. Optical radiation is introduced into the fiber from a source which may be either coherent or incoherent. An electrical current is applied to the portion of the electrically conducting optical fiber and a magnetic field is applied to the current-carrying optical fiber. A known value of one permits a determination of the presence or absence of the other through electromotive forces on a metallic conductor in a magnetic field, which are used to induce differential phase shifts (coherent optical radiation input) or losses (incoherent optical radiation input) between the fiber modes. These phase shifts or losses are detected by a suitable detector. For a magnetic field of 1 kGauss, good linearity is obtained in the 5 to 2,000 mA current range. Magnetic fields of about 0.