Cybel, Llc.

Triquint Technology Holding Co.

Robert E Tench

Jean-Marc P Delavaux

Alexandre Amavigan

Clement Romano

Joseph Michael Freund

Frank Stephen Walters

Thomas Gordon Beck Mason

Joseph Patrick Reynolds

A fiber-based optical amplifier for operation at an eye-safe input signal wavelength λwithin the 2 μm region is formed to include a section of Holmium (Ho)-doped optical gain fiber. The pump source for the fiber amplifier is particularly configured to provide pump light at a wavelength where the absorption coefficient of the Ho-doped optical gain fiber exceeds its gain coefficient (referred to as an 'absorption-dominant pump wavelength'), and is typically within the range of 1800-1900 nm. The selection of an absorption-dominant pump wavelength limits the spontaneous emission of the pump from affecting the amount of gain achieved at the higher wavelength end of the operating region. The amount of crosstalk between the signal wavelength and pump wavelength is also reduced (in comparison to using the conventional 1940 nm pump wavelength).

Efficient in-band pumping of Holmium-doped optical fiber amplifiers

A hybrid optical amplifier is proposed that includes a preamplifier element formed of single-clad Ho-doped optical fiber and a power amplifier element formed of single-clad Tm-doped (or Tm&#x2014;Ho co-doped) optical fiber. The preamplifier is used to impart gain to an input signal propagating at a wavelength &#x3bb;in the presence of a first pump beam operating at &#x3bb;, creating an amplified output over a defined transmission bandwidth. The power amplifier element is disposed at the output of the preamplifier element and provides an additional level of gain to the output of the preamplifier element in the presence of a second pump beam operating at &#x3bb;. A passband filter may be used between the preamplifier and the power amplifier to ensure that only wavelength components within the defined transmission bandwidth are applied as an output to the power amplifier.

Broadband hybrid optical amplifier operation in eye-safe wavelength region

A broadband optical amplifier for operation in the 2 &#x3bc;m visible wavelength band is based upon a single-clad Ho-doped fiber amplifier (HDFA). A compact pump source uses a combination of discrete laser diode with a fiber laser (which may be a dual-stage fiber laser) to create a pump output beam at a wavelength associated with creating gain in the presence of Ho ions (an exemplary pump wavelength being 1940 nm). The broadband optical amplifier may take the form of a single stage amplifier or a multi-stage amplifier, and may utilize a co-propagating pump and/or a counter-propagating pump arrangement.

Broadband Ho-doped optical fiber amplifier

A broadband optical amplifier for operation in the 2 &#x3bc;m visible wavelength band is based upon a single-clad Tm-doped fiber amplifier (TDFA). A compact pump source uses a combination of low-power laser diode with a fiber laser to provide a multi-watt pump beam without needing to include thermal management and/or pump wavelength stability components. The broadband optical amplifier is therefore able to be relatively compact device with fiber coupled output powers of &#x3e;0.5 W CW, high small signal gain, low noise figure, and large OSNR, important for use as a versatile wideband preamplifier or power booster amplifier.

Broadband Tm-doped optical fiber amplifier

A multi-stage thulium-doped (Tm-doped) fiber amplifiers (TDFA) is based on the use of single-clad Tm-doped optical fiber and includes a wavelength conditioning element to compensate for the nonuniform spectral response of the initial stage(s) prior to providing power boosting in the output stage. The wavelength conditioning element, which may comprise a gain shaping filter, exhibits a wavelength-dependent response that flattens the gain profile and output power distribution of the amplified signal prior to reaching the output stage of the multi-stage TDFA. The inclusion of the wavelength conditioning element allows the operating bandwidth of the amplifier to be extended so as to encompass a large portion of the eye-safe 2 &#x3bc;m wavelength region.

Tm-doped fiber amplifier utilizing wavelength conditioning for broadband performance

A doped fiber amplifier is proposed that includes both a Ho-doped amplifier (used as a preamplifier) and a Tm-doped amplifier (used as a power amplifier). The Ho-doped preamplifier typically uses a single clad (SC) optical fiber as the gain element, with both the propagating signal and pump beam introduced into the Ho-doped core of the SC fiber. The Tm-doped power amplifier typically utilizes a double clad (DC) optical fiber as the gain element, which allows for a multimode pump to propagate within the Tm-doped core region and inner cladding, providing efficient high power amplification of the signal received at its input.

Optical fiber amplifier for operation in two micron wavelength region

An electroabsorption modulator comprises a tandem arrangement of a conventional electroabsorption (EA) modulator element and a phase modulator element. The EA modulator element is driven by the digital data signal and the phase modulator is driven by a chirp tuning control signal, such as the complement of the data signal. By controlling the amplitude and/or bias of the chirp tuning control signal, the frequency chirp of the intensity-modulated output signal from the EA modulator element can be controlled.

Growing community of inventors

Allentown, PA, United States of America

Robert E Tench