Abstract: Apparatus and methods for monitoring the wavelength of laser radiation and that provide a temperature-corrected error signal responsive to the deviation of the wavelength of the laser radiation from a nominal wavelength is disclosed. The apparatus includes a least one optical filter for filtering the laser radiation according to at least one spectral filter function to produce filtered laser radiation and at least one optical detector for detecting the filtered laser radiation to produce a first detected signal. The apparatus also includes a temperature sensor for sensing temperature characteristic of at least the optical filter and processing circuitry for providing a temperature-corrected output signal responsive to the deviation of the wavelength of the laser radiation from the nominal wavelength.

Abstract: Disclosed is an optical fiber feedthrough that meets the industry load standard of 1 kg. The optical fiber feedthrough includes a length of optical fiber including a buffer layer and a core. The length of fiber extends along a longitudinal axis and typically through a passage in a package wall for communicating an optical signal between the exterior and the interior of the package. The optical fiber feedthrough includes a volume of bonding agent adhering to the buffer layer and to a bonding surface integral with the package, the volume of bonding agent disposed for asymmetrically securing the fiber to the package such that a load of less than approximately 1 kg applied to a first end of the length of fiber substantially not transmitted to the other end of the length of fiber. The invention also includes feedthrough assembly having a feedthrough to which the length of optical fiber is asymmetrically secured. The feedthrough body can be secured to the package wall of the optical package.

Abstract: An apparatus for monitoring and controlling the wavelength of laser radiation includes at a least one optical filter for receiving laser radiation and for transmitting and reflecting first and second filtered beams, respectively. Alternatively, the first and second beams may be transmitted by separate filters. The beams are filtered according to respective first and second spectral filter functions that cross at at least one crossing wavelength. A beam comparison element compares the first and second filtered beams and produces an error signal representative of the deviation of the wavelength of the laser radiation from a set-point wavelength. The beam comparison element can include first and second optical detectors and an error circuit for producing the error signal by taking a ratio or the difference of the signals detected by the detectors.

Abstract: An integrated optical transmitter for use in an optical system includes an optical head assembly having an optical beam generator for providing an optical beam and a lens assembly for collecting the optical beam and generating therefrom a formed optical beam. Interface optics receive the formed optical beam for coupling the beam to a modulator so as to reduce nsertion loss to the optical beam. The optical modulator receives the optical beam from the interface optics and provides a modulated optical beam in response to received modulation signals. The optical modulator is coupled to the interface optics to be in a fixed relationship therewith. The integrated optical transmitter can include a means for sampling the optical beam and controlling the temperature of and/or the current supplied to the optical beam generator for controlling the wavelength of the optical transmitter.

Abstract: Method and apparatus are disclosed for the stable control of electrooptic devices, such as for providing a stable bias point for operation of a lithium niobate interferometer-type modulator. The bias point of the modulator is thermally controlled by providing a selected difference in the temperatures of optical waveguide lengths of the interferometer. Heaters can be disposed with the lithium niobate substrate for transferring thermal energy with the optical waveguide lengths. A thermally conductive element can be disposed adjacent the optical waveguide lengths to act as “heat spreaders” to facilitate providing the selected difference in temperature. The invention also includes phase shifters, attenuators, and other optical devices formed from single and multiple optical waveguide lengths propagating separate optical beams.

Abstract: An optical amplifier for amplifying a plurality of signal components of a multi-wavelength optical beam passing through an optical fiber includes a portion of the optical fiber doped with a rare earth ion to amplify the optical signal wherein the gain spectrum as a function of the wavelength is nonuniform. The optical amplifier further includes a gain flattening module to compensate for the nonuniform gain spectrum of the doped fiber by attenuating each of the channels of the amplified signal to equalize the gain. A gain equalization module compensates for varying gain fluctuations due to the adding and subtracting of signal components. The gain equalization module adjusts dynamically each signal component of the optical beam such that the amplitudes of the signal components are substantially equal, in response to a plurality of control signals. Each control signal is representative of the degree of attenuation required to equalize the signal components.

Abstract: An optical fiber having a core, a cladding layer, a buffer layer, and a midsection for forming a hermetic seal to the fiber. First and second sections of a length of the optical fiber are separated by the midsection that includes a jacket hermetically sealed to the fiber, the jacket having a hermetically sealable outer surface. First and second stress relief joints are formed between the jacket and the buffer layers of the first and second sections of the length of the fiber. A method is disclosed for fabricating the optical fiber having a hermetically sealable section.

Abstract: A loop status monitor for determining the magnitude of the power output of each signal component of a multi-wavelength optical beam includes a dense wavelength division demultiplexing arrayed waveguide and a detector array. The detector elements are butt-coupled to each respective output of the waveguide to reduce insertion loss and cost. The detector array is formed of planar silica material having a plurality of precision ion implanted regions that separate the optical beam into its respective signal components. The signal components are directed to a corresponding detector element of the detector array. Each detector element includes a photodiode that converts the optical beam to an electrical signal indicative of the amplitude of the power of the channel.

Abstract: A method for use in fabricating an electro-optic structure on a substrate having an optical waveguide formed in an upper surface thereof, comprises the steps of forming a layer of organic dielectric material, such as a benzocyclobutene (BCB) resin, on the substrate upper surface, forming an interface layer on an upper surface of the organic dielectric layer, and forming an electrically isolated electrode on an upper surface of the interface layer such that an electrical field can be induced in the optical waveguide.

Abstract: A ferroelectric material 44 is selectively poled using laser light 14 capable of being absorbed by the material 44, a shutter 18 for turning the light on and off, a variable attenuator 28, with a beam splitter 31 and an optical detector 31a, to set the laser power level, a lens 32 to provide focused laser light 14d, a mirror 36 driven by a motor 40 (mirror-scanner) to direct the light to the regions to be poled, and an electric field applied by electrodes 68, 70. A computer 24 provides automatic control over selective poling of the material 44 by controlling the shutter 18, variable attenuator 28, mirror 36 position, and the direction of the applied electric field. A temperature sensor 52 provides temperature feedback to ensure proper laser power and dwell time. In the alternative, the material 44 is covered with a mask 604 and scanned with the laser to provide selective pole reversal.

Abstract: A variable chirp electro-optic modulator is provided that uses a single modulation signal. The modulator has several optical paths in the proximity of one or more modulation electrodes which are driven equally by a single modulation source. The amount of chirp desired of the modulator is controlled by varying the optical amplitude or phase of the light in the different paths.