United Technologies Corporation

Jds Uniphase Corporation

Uniphase Telecommunications Products, Inc.

Other

3m Innovative Properties Company

Uniphase Corporation

Gary A Ball

Gerald Meltz

William H Glenn

Karl M Kissa

Leon A Newman

Timothy C Munks

Paul E Dunn

Ronald T Logan, Jr

Robert W Ade

Eitan Gertel

Paul Sanders

Yi Zhang

Timothy J Bailey

Paul Eric Sanders

Frederick J Leonberger

James Craig Novack

Bryon J Cronk

Richard A Meinzer

William W Morey

Harmeet Singh

Michael C Fowler

Bruce A Rabine

Daniel J Fritz

Francis X D'Amato, Deceased

An integrated optical transmitter for use in an optical system has an optical head assembly with an optical beam generator for providing an optical beam and a lens assembly collecting the optical beam and generating therefrom a formed optical beam. Interface optics receives the formed optical beam and provides optical coupling so as to minimize insertion loss to the optical beam. Also included is an optical modulator for receiving the optical beam from the interface optics and for providing 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.

Integrated wavelength-select transmitter

A mini-bend optical arrangement and an associated method are described. This arrangement is designed to change the directional orientation of a light path using optical fiber. A first and a second fiber optic member define first and second light paths, respectively, which first and second members include a numerical aperture and which introduce substantial bend losses upon being bent at less than a predetermined bend radius. The first and second fiber optic members are arranged along the first and second paths preferably bent by less than the predetermined bend radius. A bent fiber optic member including a numerical aperture that is greater than the numerical aperture of the first and second fiber optic members interconnects the first and second fiber optic members so as to define a continuous light path including the first and second light paths with the bent member defining a curved path therebetween such that the bent fiber optic member has a bend radius which is less than the predetermined bend radius but which avoids introducing substantial bend losses. The mini-bend arrangement is useful in highly advantageous miniaturized device configurations. As a first example, a miniaturized add/drop module is introduced. As other examples, miniaturized tree couplers, EDFA modules and WDM modules are introduced.

Fiber mini-bend light guide

The present invention is a process for manufacturing an optical fiber Bragg grating, which in a preferred embodiment includes the steps of: (a) removing at least a portion of a removable coating on an optical fiber element in at least one predetermined section to sufficiently expose the optical fiber in the section for a subsequent treatment by a source of optical radiation; (b) fixing the at least one section with respect to the source of optical radiation; (c) directing optical radiation from the source into the optical fiber to produce at least one Bragg grating in the at least one section; and (d) covering the at least one section. The present invention also extends to an apparatus for carrying out the process steps described above, which includes means for coating removal, means for fiber immobilization, means for writing a Bragg grating, and means for packaging.

Incremental method of producing multiple UV-induced gratings on a single optical fiber

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. The optical head assembly and the modulator can be compliantly mounted to a mounting surface reducing the effects of thermal stress on the performance of the optical transmitter.

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. The respective control signals are generated by a loop status monitor that includes a waveguide for demultiplexing the optical beam, and a detector array that determines the amplitude of each signal component. A controller generates the control signals in dependence of the amplitude of the signal components.

Dynamic optical amplifier

A rare earth doped fiber for use in a fiber laser is presented. The fiber laser uses a single stripe broad area pump diode permits Yb lasing in its 3-level transition at 980 nm preferentially over the 1010 nm 4-level transition. The present fiber laser is characterized by a dual cladding fiber geometry which includes an inner rare earth doped single mode core. There is an inner cladding designed to be a multimode pump core for the pump light. The pump core is followed by a final cladding to confine the pump radiation. The present laser matches the larger/outer mode field to that of a single stripe broad area diode in order to maximize the pump intensity.

High power three level fiber laser and method of making same

An apparatus for use in selectively adding or dropping channels in an optical network includes an optical circulator and an array of programmable fiber Bragg gratings. Each fiber Bragg grating is a narrow ban reflective element which can be tuned on or off of an ITU standard wavelength division multiplex channel so that the channel is either fully reflected or transmitted by the grating. The addition or subtraction of signal channels is operated by a controller which operates the individual fiber Bragg gratings between transmissive and reflective states.

Programmable add-drop module for use in an optical circuit

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.

Loop status monitor for determining the amplitude of the signal

A fiber laser 26 including a rare-earth doped fiber laser cavity 32 delimited by a pair of reflective elements 28,30, such as Bragg gratings, is tuned by compressing the cavity 32 and the gratings 28,30. Because an optical fiber is a much stronger under compression than in tension, the laser 26 is tunable over a much broader range than conventional tension/stretching techniques.

Compression-tuned fiber laser

An emedded Bragg grating laser Master-Oscillator and Power-Amplifier (MOPA), includes an optical waveguide which receives and propagates pump light of a predetermined wavelength launched into the optical waveguide; a first master oscillator laser, disposed in the waveguide in the path of the pump light, the laser having a laser cavity disposed between a first pair of reflectors and having a first laser gain medium within the first laser cavity which emits first lasing light in response to the pump light, the first reflectors reflecting a predetermined amount of the first lasing light within the first laser cavity and passing a predetermined amount of the first fusing light as first output laser light from the first laser, the first reflectors passing the pump light through the first laser; at least one of the first reflectors comprises a Bragg grating; and an optical waveguide power amplifier, disposed in the path of the first output laser light and the pump light, and having a first amplifier gain medium therein which emits first amplified laser light in response to the pump light and the first output laser light.

Embedded Bragg grating laser master-oscillator and power-amplifier

An efficient wavelength multiplexer/demultiplexer includes a plurality of 2.times.2 optical couplers 122,180,200,220, each having a pair of matched gratings 130,142; 182,184; 202,204; and 222,224, having bandpass wavelengths .lambda..sub.1, .lambda..sub.2, .lambda..sub.3, .lambda..sub.4, respectively, attached to two of the ports. An input signal 116 enters a port 120 and is split and reflected off the gratings 130,142 and then recombined so as to provide all the input signal 116 at an output port 150 and no reflection out of the port 120. Another input signal 154 is incident on the grating 142 which is passed by the grating 142 and is coupled onto the output port 150 with the signal 116 as a signal 160. A similar arrangement exists for the other couplers 180,200,220 connected in series, each of which adds another input wavelength. Alternatively, in a de-multiplexing application the signal 116 may be broadband and the signals 154,190,206,230 would be separate output wavelengths.

Efficient optical wavelength multiplexer/de-multiplexer

A dual wavelength pumped low noise fiber laser includes a fiber laser 10 comprising a pair of Bragg gratings 14,16 at opposite ends of a fiber laser cavity 18 which is co-doped with two rare-earth dopants, Er.sup.+3 Yb.sup.+3, so as to allow lasing to occur at a lasing wavelength .lambda..sub.L. A first pump signal 20 efficiently pumps the Yb to the excited state and the Yb energy is transitioned to the Er atoms which ultimately lase at the desire lasing frequency. Because Yb is pumped so efficiently, high pump absorption is achieved, thereby providing high laser output power and, consequently, reduced RIN. Simultaneously, a second pump signal 52 directly pumps the Er at a different wavelength .lambda..sub.P2 which populates the lasing transition more quickly, thereby allowing sufficient bandwidth of a closed loop control on the second pump signal 52 to control low frequency RIN spiking due to relaxation oscillations in the laser.

Dual-wavelength pumped low noise fiber laser

A birefringent active fiber laser sensor includes one or more fiber lasers 12, 14, 16, each having a pair of Bragg gratings 18, 20, embedded in a fiber 10 and excited by a common pump light 30. At least one of the lasers 12, 14, 16 has a laser cavity wit a predetermined birefrigence and a lasing light at a first lasing frequency along a first polarization axis, and at a second fusing frequency along a second polarization axis. A difference frequency between the first and the second lasing frequencies is related to the magnitude of the birefringence, and the birefringence varies in response to a perturbation. Output light 104 from each of the lasers 12,14,16 is fed to a defraction grating 106 which splits the beam 104 into different wavelength groups, each group having the two lasing frequencies and polarizations of a given laser. Each wavelength group is fed to a corresponding analyzer 122-126 which combines the first and second frequencies and polarizations for each laser to form a lower difference or 'beat' frequency, thereby allowing lower frequency detection devices 138-142 to be used.

Birefringent active fiber laser sensor

A single polarization fiber and/or amplifier includes a non-polarization preserving fiber 10 having a fiber grating tap 12 which has a predetermined length and strength (.DELTA.n/n) and is oriented at a predetermined angle .theta. and has a grating spacing D so as to couple-out of the fiber 10 a predetermined amount of one polarization 24 over a predetermined wavelength range of an input light 16 and pass the other polarization 28 as output light 26, the grating length being substantially the length of the fiber 10. Alternatively, all or a portion of the fiber 10 may be doped to form a polarization sensitive optical amplifier.

Single polarization fiber and amplifier

An amplitude modulated continuous wave (AMCW) laser radar (ladar) system is provided with a dual-wavelength source 10 which provides a dual wavelength signal 12 (one fixed and one chirped) which is launched down a fiber 28 to a target 38 and reflected back along the fiber 28 and the return detected by a detector 52. The transmitted signal is detected by a detector 56. The detectors 52, 56 provide an electrical return beat signal and reference beat signal, respectively, indicative of the difference between the wavelengths incident thereon. The signals are fed to a frequency mixer 60 which subtracts the two beat frequencies and signal processing logic 64 computes the distance to the target 38. Using dual wavelengths and beat frequencies provides a much broader chirp bandwidth than conventional ladar techniques, and allows for higher power sources, thereby reducing range error.

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Simsbury, CT, United States of America

Gary A Ball