Abstract: Some embodiments presented here relate to chemical sensors with enhanced sensitivity and selectivity. In an embodiment, the sensor is a composite thin film that comprises (e.g., is made of) chemically-modified carbon black and a chemically-sensitive polymer base. By grafting gold nanoparticles on carbon black, the number of binding sites on the sensor thin film is increased, thereby increasing the sensitivity. Furthermore, ligand attached gold nanoparticles are grafted on carbon black to increase the binding sites on the sensor thin film in some embodiments, which results in increased sensitivity as well as improved selectivity in some cases.

Abstract: Some embodiments presented here relate to chemical sensors with enhanced sensitivity and selectivity. In an embodiment, the sensor is a composite thin film that comprises (e.g., is made of) chemically-modified carbon black and a chemically-sensitive polymer base. By grafting gold nanoparticles on carbon black, the number of binding sites on the sensor thin film is increased, thereby increasing the sensitivity. Furthermore, ligand attached gold nanoparticles are grafted on carbon black to increase the binding sites on the sensor thin film in some embodiments, which results in increased sensitivity as well as improved selectivity in some cases.

Abstract: A laser amplifier includes a pump source and an optically active fiber having an input portion configured to receive a signal source and an output portion. The pump source is optically coupled to the optically active fiber. The laser amplifier also includes an output fiber optically coupled to the output portion of the optically active fiber. The output fiber includes a rare-earth element. The laser amplifier further includes a beam expansion section joined to the output fiber.

Abstract: A laser system includes an injection laser source having an output and operable to provide a laser output characterized by a first wavelength, a first linewidth, an output power. The laser system also includes a tunable pulsed source characterized by a gain bandwidth. The tunable pulsed source is operable to provide an output signal having an average power. The output signal includes a plurality of optical pulses. Each of the plurality of optical pulses is characterized by a second wavelength, a second linewidth, and a peak power. The laser system further includes an optical combiner having a first port coupled to the output of the injection laser source, a second port coupled to the tunable pulsed source, and a third port.

Abstract: A method of laser scribing a CdTe solar cell structure includes providing a laser operable to produce an optical pulse. The optical pulse is characterized by a temporal profile having a first power level during a first portion of the optical pulse and a second power level less than the first power level during a second portion of the optical pulse. The method also includes directing the optical pulse to impinge on the CdTe solar cell structure. The CdTe solar cell structure includes a substrate, a transmission spectrum control layer adjacent the substrate; a barrier layer adjacent the transmission spectrum control layer, and a conductive layer adjacent the barrier layer. The method further includes initiating a removal process for the conductive layer and terminating the removal process prior to removing the barrier layer.

Abstract: A series of laser pulses in a pulse train, each pulse with a beneficial temporal power shape instead of the conventional laser temporal power shape, scribes a line in a thin film of material on a substrate. The beneficial temporal pulse shape has a spike/plateau chair shape or a square pulse shape. Scribing a line in the thin film is achieved by placing the series of laser pulse spots on the line to be scribed such that there is an overlapping area between adjacent laser pulse spots along the line. The use of a series of laser pulses with beneficial pulse shape to scribe a line in the thin film results in a better quality and cleaner scribing process compared to that achieved with the conventional pulse shape.

Abstract: A method of operating a fiber amplifier characterized by a spectral gain curve includes providing an input signal at a signal wavelength. The signal wavelength lies within an in-band portion of the spectral gain curve extending from a first in-band wavelength to a second in-band wavelength, the in-band portion being characterized by a first amplitude range. The method also includes providing pump radiation at a pump wavelength. The pump wavelength is less than the signal wavelength. The method further includes coupling the pump radiation to the fiber amplifier and amplifying the input signal to generate an output signal. All portions of the spectral gain curve at wavelengths less than the first in-band wavelength and greater than the pump wavelength are characterized by a second amplitude less than or equal to 10 dB greater than the first amplitude range.

Abstract: A method of operating a fiber amplifier characterized by a spectral gain curve includes providing an input signal at a signal wavelength. The signal wavelength lies within an in-band portion of the spectral gain curve extending from a first in-band wavelength to a second in-band wavelength, the in-band portion being characterized by a first amplitude range. The method also includes providing pump radiation at a pump wavelength. The pump wavelength is less than the signal wavelength. The method further includes coupling the pump radiation to the fiber amplifier and amplifying the input signal to generate an output signal. All portions of the spectral gain curve at wavelengths less than the first in-band wavelength and greater than the pump wavelength are characterized by a second amplitude less than or equal to 10 dB greater than the first amplitude range.

Abstract: A method of operating a fiber amplifier characterized by a spectral gain curve includes providing an input signal at a signal wavelength. The signal wavelength lies within an in-band portion of the spectral gain curve extending from a first in-band wavelength to a second in-band wavelength, the in-band portion being characterized by a first amplitude range. The method also includes providing pump radiation at a pump wavelength. The pump wavelength is less than the signal wavelength. The method further includes coupling the pump radiation to the fiber amplifier and amplifying the input signal to generate an output signal. All portions of the spectral gain curve at wavelengths less than the first in-band wavelength and greater than the pump wavelength are characterized by a second amplitude less than or equal to 10 dB greater than the first amplitude range.

Abstract: A laser amplifier includes a pump source and an optically active fiber having an input portion configured to receive a signal source and an output portion. The pump source is optically coupled to the optically active fiber. The laser amplifier also includes an output fiber optically coupled to the output portion of the optically active fiber. The output fiber includes a rare-earth element. The laser amplifier further includes a beam expansion section joined to the output fiber.

Abstract: A tunable pulsed laser source comprising a seed source adapted to generate a seed signal and an optical circulator. The optical circulator includes a first port coupled to the seed source, a second port, and a third port. The laser source also includes an amplitude modulator characterized by a first side and a second side. The first side is coupled to the second port of the optical circulator. The laser source further includes a first optical amplifier characterized by an input end and a reflective end including a spectral-domain reflectance filter. The input end is coupled to the second side of the amplitude modulator. Moreover, the laser source includes a second optical amplifier coupled to the third port of the optical circulator.

Abstract: A method of laser scribing a CdTe solar cell structure includes providing a laser operable to produce an optical pulse. The optical pulse is characterized by a temporal profile having a first power level during a first portion of the optical pulse and a second power level less than the first power level during a second portion of the optical pulse. The method also includes directing the optical pulse to impinge on the CdTe solar cell structure. The CdTe solar cell structure includes a substrate, a transmission spectrum control layer adjacent the substrate; a barrier layer adjacent the transmission spectrum control layer, and a conductive layer adjacent the barrier layer. The method further includes initiating a removal process for the conductive layer and terminating the removal process prior to removing the insulating layer.

Abstract: A tunable pulsed laser source comprising a seed source adapted to generate a seed signal and an optical circulator. The optical circulator includes a first port coupled to the seed source, a second port, and a third port. The laser source also includes an amplitude modulator characterized by a first side and a second side. The first side is coupled to the second port of the optical circulator. The laser source further includes a first optical amplifier characterized by an input end and a reflective end including a spectral-domain reflectance filter. The input end is coupled to the second side of the amplitude modulator. Moreover, the laser source includes a second optical amplifier coupled to the third port of the optical circulator.

Abstract: A series of laser pulses in a pulse train, each pulse with a beneficial temporal power shape instead of the conventional laser temporal power shape, scribes a line in a thin film of material on a substrate. The beneficial temporal pulse shape has a spike/plateau chair shape or a square pulse shape. Scribing a line in the thin film is achieved by placing the series of laser pulse spots on the line to be scribed such that there is an overlapping area between adjacent laser pulse spots along the line. The use of a series of laser pulses with beneficial pulse shape to scribe a line in the thin film results in a better quality and cleaner scribing process compared to that achieved with the conventional pulse shape.

Abstract: Methods and systems are provided to reduce stimulated Brillouin scattering in high power optical fiber amplifiers. In an embodiment, a seed source includes a narrow linewidth semiconductor laser driven with a current ramp that simultaneously sweeps the optical power and the lasing frequency at a rate fast enough to reduce stimulated Brillouin scattering.

Abstract: A series of laser pulses in a pulse train, each pulse with a predetermined temporal power shape, scribes a line in a thin film of material on a substrate. The predetermined temporal pulse shape has a fast risetime and fast falltime and a pulse length between 10% power points of less than 10 ns. Scribing a line in the thin film is achieved by placing the series of laser pulse spots on the line to be scribed such that there is some overlapping area between adjacent laser pulse spots along the line. The use of a series of laser pulses with the predetermined pulse shape to scribe a line in the thin film results in a better quality and cleaner scribing process compared to that achieved with a conventional pulse shape.

Abstract: A method of operating a fiber amplifier characterized by a spectral gain curve includes providing an input signal at a signal wavelength. The signal wavelength lies within an in-band portion of the spectral gain curve extending from a first in-band wavelength to a second in-band wavelength, the in-band portion being characterized by a first amplitude range. The method also includes providing pump radiation at a pump wavelength. The pump wavelength is less than the signal wavelength. The method further includes coupling the pump radiation to the fiber amplifier and amplifying the input signal to generate an output signal. All portions of the spectral gain curve at wavelengths less than the first in-band wavelength and greater than the pump wavelength are characterized by a second amplitude less than or equal to 10 dB greater than the first amplitude range.

Abstract: A laser system includes an injection laser source having an output and operable to provide a laser output characterized by a first wavelength, a first linewidth, an output power. The laser system also includes a tunable pulsed source characterized by a gain bandwidth. The tunable pulsed source is operable to provide an output signal having an average power. The output signal includes a plurality of optical pulses. Each of the plurality of optical pulses is characterized by a second wavelength, a second linewidth, and a peak power. The laser system further includes an optical combiner having a first port coupled to the output of the injection laser source, a second port coupled to the tunable pulsed source, and a third port.

Abstract: A system for fiber optic packaging includes a first substrate and a first deformable pad coupled to the first substrate. The first deformable pad is characterized by a thermal conductivity greater than 1 W/mK. The system also includes a fiber coil having at least a portion embedded in the first deformable pad to provide physical contact between the at least a portion of the fiber coil and the first deformable pad. The system further includes a second substrate coupled to the fiber coil and at least a portion of the first deformable pad.

Abstract: A series of laser pulses in a pulse train, each pulse with a predetermined temporal power shape, scribes a line in a thin film of material on a substrate. The predetermined temporal pulse shape has a fast risetime and fast falltime and a pulse length between 10% power points of less than 10 ns. Scribing a line in the thin film is achieved by placing the series of laser pulse spots on the line to be scribed such that there is some overlapping area between adjacent laser pulse spots along the line. The use of a series of laser pulses with the predetermined pulse shape to scribe a line in the thin film results in a better quality and cleaner scribing process compared to that achieved with a conventional pulse shape.