claudio coriasso - Academia.edu (original) (raw)

Papers by claudio coriasso

Applied Sciences

A statistical experimental investigation of the characteristic changes associated with the degree... more A statistical experimental investigation of the characteristic changes associated with the degree-of-polarization reduction of high-power laser diodes is reported. A simple model accounting for the stress-induced degree-of-polarization changes through the photoelastic effect is introduced to qualitatively support the experimental results. Functional characteristics addressed in the investigation are the threshold current, the slope efficiency, the polarization-resolved far field and near field, and the beam parameter product. Model outcomes and measured parameters related to different degree-of-polarization values have proven very useful for device optimization aimed to polarization multiplexing applications.

High-Power Diode Laser Technology XX, 2022

High-Power Diode Laser Technology XIX, 2021

This paper reports a multi-emitter laser module realization, based on internally developed InGaAs... more This paper reports a multi-emitter laser module realization, based on internally developed InGaAs/GaAs 190 μm ridge High Power Diode Lasers (HPDL), emitting at 976 nm. Single diode lasers shown a highly efficient power conversion and good emitted beam characteristics together with excellent long term reliability. The multi-emitter laser module, using 20 diodes polarization and spatially multiplexed, demonstrated up to 350 W of output power at 976 nm; the absence of fiber coupling degradation at high bias currents, thanks to the limited beam blooming from the laser diodes, ensure a good linearity in the operating conditions. The package has a compact footprint of 54 mm x 140 mm, with an output fiber of 200 um core / 220 um cladding, and 95 % of the emitted power is within 0.16 numerical aperture (N.A.). Present realization of high-power multi-emitter semiconductor laser source is suitable for production of high power single modules fiber laser, moreover contributing to an important reduction of the overall fiber laser cost by effectively reducing the number of the pump modules.

High-Power Diode Laser Technology XVIII, 2020

This paper reports preliminary performances of a multiemitter diode laser module using ten spatia... more This paper reports preliminary performances of a multiemitter diode laser module using ten spatially multiplexed Distributed Bragg Reflector - High Power Diode Laser (DBR-HPDL) chip, emitting 100 W CW in the 920 nm range, with 95 % of power in 0.17 N.A., on a 135 um core / 155 um cladding multimode fiber, and stabilized spectrum width of only 0.6 nm. Diode chip implemented an integrated multiple-orders Electron Beam Lithography (EBL) optical confining grating, stabilizing on same wafer multiple wavelengths using a manufacturable, reliable and high yield technology. Up to three pitches, DBR-HPDLs 2.5 nm spaced have been demonstrated on same wafer with excellent uniformity of performances across the wafer and emitted wavelengths. Since the absence of any wavelength locking optical element in the collimated beam path, multiemitter module of DBRHPDL was assembled and tested in the production line using standard assembly process flow and without requiring any special alignment, as maturi...

This paper reports a DBR High Power Diode Laser (DBR-HPDL) realization, emitting up to 14W CW in ... more This paper reports a DBR High Power Diode Laser (DBR-HPDL) realization, emitting up to 14W CW in the 920nm range. Key feature is the use of a multiple-order Electron Beam Lithography (EBL) optical confining grating, stabilizing on same wafer multiple wavelengths by a manufacturable and reliable technology. In present paper, on the same wafer, three pitches DBR-HPDLs 2.5nm spaced have been demonstrated with excellent characteristics of power, spectral purity and stability. Moreover, excellent uniformity of performances across the wafer with different emitted wavelengths demonstrates the maturity of proposed technology for high yield, high volume laser diode production for wavelength stabilized applications.

Journal of Physics: Photonics, 2020

This paper reports a wavelength-stabilized high-power diode laser emitting up to 14 W CW in the 9... more This paper reports a wavelength-stabilized high-power diode laser emitting up to 14 W CW in the 9xx nm range. Wavelength stabilization is achieved by a distributed Bragg reflector (DBR) monolithically integrated in the diode laser chip. Key features are identical layer epitaxy (ILE) and the use of a multiple-order electron beam lithography (EBL) optical confining grating. ILE avoids any regrowth or complex technology processes, while EBL multiple-order grating allows narrow-band back reflection and effective lateral optical confinement, and makes it possible to stabilize multiple wavelengths on the same wafer using a manufacturable and reliable technology. DBR diode lasers with different pitches, whose wavelengths were 3 nm spaced, were fabricated and high spectral purity (95% optical power within about 0.6 nm) and wavelength stability were measured. Moreover, the high uniformity of performances across the wafer with different emitted wavelengths demonstrates the maturity of the pro...

Optical Fiber Communication Conference and National Fiber Optic Engineers Conference, 2009

R. Paoletti, Member, IEEE, M. Agresti, D. Bertone, C. Bruschi, S. Codato, C. Coriasso, R. Defranc... more R. Paoletti, Member, IEEE, M. Agresti, D. Bertone, C. Bruschi, S. Codato, C. Coriasso, R. Defranceschi, P. Dellacasa, M. Diloreto, RY Fang, P. Gotta, G. Meneghini, C. Rigo, E. Riva, G.Roggero, A. Stano, M. Meliga, Senior Member, IEEE TTC - Avago Technologies Italy, ...

Thin Solid Films, 1991

... The lattice mismatch was evaluated from the X-ray rocking curve obtained with a double-crysta... more ... The lattice mismatch was evaluated from the X-ray rocking curve obtained with a double-crystal diffractometer. Figure 2 shows the determined energy gaps plotted us. ... Sci. Technol., .3 (1988) 365. I 1 JSA Adelabu, BK Ridley, EG Scott and GJ Davies, Semicond. Sci. ...

Journal of the Optical Society of America B, 1997

Using a widely tunable femtosecond laser source based on an optical parametric amplifier, we perf... more Using a widely tunable femtosecond laser source based on an optical parametric amplifier, we performed pump-probe measurements of the dynamics of the nonlinear transmittance on an InGaAs/InP multiplequantum well sample, with pump and probe beams tuned to the same photon energy as well as with a continuum probe. The pump photon-energy range was 0.8-1 eV. The main results are the following: (i) the ionization time of the n ϭ 1 heavy-hole excitons is 170 fs; (ii) bleaching effects were found to be instantaneous within the temporal resolution of our experiments (50 fs), irrespective of probe photon energy, for excitation within the n ϭ 1 subbands; (iii) the n ϭ 2 to n ϭ 1 intersubband transition time was 1 ps; and (iv) the relative strength of exciton-induced and carrier-induced nonlinearities depends crucially on the photon energy of the probe beam. The transmittance spectra of the multiple-quantum-well system were calculated in the presence of either a cold exciton gas or a quasi-equilibrium carrier plasma. We found that there are conditions in which the ratio of the transmittance variations induced by cold excitons and by thermalized carriers diverges, as experimentally observed.

IEEE Photonics Technology Letters, 1996

Semiconductor integrated waveguide turning mirrors (IWTM) are investigated using the beam propaga... more Semiconductor integrated waveguide turning mirrors (IWTM) are investigated using the beam propagation method. A mirror is fabricated and modeled along with realistic geometries in the presence of offset and roughness of the mirror surface. An interference effect between waves reflected at different surfaces in the device is evidenced, that has strong impact on the device performance in the case of weakly-confining structures. A widely-accepted fabrication approach is criticized in view of this effect. A solution is outlined that minimizes the losses due to either technological limitations or interference.

Applied Physics Letters, 1995

Using an infrared tunable femtosecond source, we investigate the time evolution of exciton absorp... more Using an infrared tunable femtosecond source, we investigate the time evolution of exciton absorption bleaching in InGaAs/InP quantum wells at energies slightly below the exciton absorption peak at room temperature. We find that the bleaching due to photogenerated excitons can be stronger than that due to a thermal electron/hole plasma by a factor of 40. Numerical modeling, based on many‐body theory, yields a qualitative explanation of this unusual behavior, along with its density and spectral dependence as well.

Applied Physics Letters, 1995

... El Mostafa Skouri, Patrick Martin, Laurent Chusseau, Claude Alibert, Claudio Coriasso, Domeni... more ... El Mostafa Skouri, Patrick Martin, Laurent Chusseau, Claude Alibert, Claudio Coriasso, Domenico Campi, Carmelo Cacciatore. Abstract. ... Phys. 77, 1747 (1995). RK Hickernell, DH Christensen, JG Pellegrino, J. Wang, and J.-P. Leburton, J. Appl. Phys. 75, 3056 (1994). ...

Journal of Applied Physics, 2005

We experimentally determine the band offset of strain-compensated InGaAsP-InGaAsP multiquantum-we... more We experimentally determine the band offset of strain-compensated InGaAsP-InGaAsP multiquantum-well (MQW) heterostructures, emitting at 1.55 mum, that were grown by metal-organic chemical vapor deposition. A band offset value of about 56% is found for the conduction band, which is higher than the value reported for the unstrained structure. The temperature dependence of the photoluminescence intensity shows that the unipolar detrapping

High-Power Diode Laser Technology XIX

Proceedings of SPIE - The International Society for Optical Engineering

ABSTRACT

We report both linear and nonlinear grating coupling to a planar multiple quantum well (MQW) wave... more We report both linear and nonlinear grating coupling to a planar multiple quantum well (MQW) waveguide grown by chemical beam epitaxy. We demonstrate a strong dependence of the coupling angle on the incident power in the wavelength range (lambda) equals 1.57 - 1.60 micrometers . The obtained nonlinear variation of neff were found to be negative, and on the order of 10-3, in agreement with many-body calculations performed by the authors. We show that thermal effects can be ruled out. At coupled light intensity as low as 40 mW, nonlinear switching condition was achieved; the power density to obtain the switching process is substantially lower than in previous works. As part of this work, we report the systematic investigation of the linear and nonlinear absorption properties of several InGaAs/InP MQW structures, measuring a series of transmission spectra in the region of the band edge for various pump intensities and observing large changes in the absorption coefficient. Through compa...

Physical Concepts and Materials for Novel Optoelectronic Device Applications II, 1993

Applied Sciences

A statistical experimental investigation of the characteristic changes associated with the degree... more A statistical experimental investigation of the characteristic changes associated with the degree-of-polarization reduction of high-power laser diodes is reported. A simple model accounting for the stress-induced degree-of-polarization changes through the photoelastic effect is introduced to qualitatively support the experimental results. Functional characteristics addressed in the investigation are the threshold current, the slope efficiency, the polarization-resolved far field and near field, and the beam parameter product. Model outcomes and measured parameters related to different degree-of-polarization values have proven very useful for device optimization aimed to polarization multiplexing applications.

High-Power Diode Laser Technology XX, 2022

High-Power Diode Laser Technology XIX, 2021

This paper reports a multi-emitter laser module realization, based on internally developed InGaAs... more This paper reports a multi-emitter laser module realization, based on internally developed InGaAs/GaAs 190 μm ridge High Power Diode Lasers (HPDL), emitting at 976 nm. Single diode lasers shown a highly efficient power conversion and good emitted beam characteristics together with excellent long term reliability. The multi-emitter laser module, using 20 diodes polarization and spatially multiplexed, demonstrated up to 350 W of output power at 976 nm; the absence of fiber coupling degradation at high bias currents, thanks to the limited beam blooming from the laser diodes, ensure a good linearity in the operating conditions. The package has a compact footprint of 54 mm x 140 mm, with an output fiber of 200 um core / 220 um cladding, and 95 % of the emitted power is within 0.16 numerical aperture (N.A.). Present realization of high-power multi-emitter semiconductor laser source is suitable for production of high power single modules fiber laser, moreover contributing to an important reduction of the overall fiber laser cost by effectively reducing the number of the pump modules.

High-Power Diode Laser Technology XVIII, 2020

This paper reports preliminary performances of a multiemitter diode laser module using ten spatia... more This paper reports preliminary performances of a multiemitter diode laser module using ten spatially multiplexed Distributed Bragg Reflector - High Power Diode Laser (DBR-HPDL) chip, emitting 100 W CW in the 920 nm range, with 95 % of power in 0.17 N.A., on a 135 um core / 155 um cladding multimode fiber, and stabilized spectrum width of only 0.6 nm. Diode chip implemented an integrated multiple-orders Electron Beam Lithography (EBL) optical confining grating, stabilizing on same wafer multiple wavelengths using a manufacturable, reliable and high yield technology. Up to three pitches, DBR-HPDLs 2.5 nm spaced have been demonstrated on same wafer with excellent uniformity of performances across the wafer and emitted wavelengths. Since the absence of any wavelength locking optical element in the collimated beam path, multiemitter module of DBRHPDL was assembled and tested in the production line using standard assembly process flow and without requiring any special alignment, as maturi...

This paper reports a DBR High Power Diode Laser (DBR-HPDL) realization, emitting up to 14W CW in ... more This paper reports a DBR High Power Diode Laser (DBR-HPDL) realization, emitting up to 14W CW in the 920nm range. Key feature is the use of a multiple-order Electron Beam Lithography (EBL) optical confining grating, stabilizing on same wafer multiple wavelengths by a manufacturable and reliable technology. In present paper, on the same wafer, three pitches DBR-HPDLs 2.5nm spaced have been demonstrated with excellent characteristics of power, spectral purity and stability. Moreover, excellent uniformity of performances across the wafer with different emitted wavelengths demonstrates the maturity of proposed technology for high yield, high volume laser diode production for wavelength stabilized applications.

Journal of Physics: Photonics, 2020

This paper reports a wavelength-stabilized high-power diode laser emitting up to 14 W CW in the 9... more This paper reports a wavelength-stabilized high-power diode laser emitting up to 14 W CW in the 9xx nm range. Wavelength stabilization is achieved by a distributed Bragg reflector (DBR) monolithically integrated in the diode laser chip. Key features are identical layer epitaxy (ILE) and the use of a multiple-order electron beam lithography (EBL) optical confining grating. ILE avoids any regrowth or complex technology processes, while EBL multiple-order grating allows narrow-band back reflection and effective lateral optical confinement, and makes it possible to stabilize multiple wavelengths on the same wafer using a manufacturable and reliable technology. DBR diode lasers with different pitches, whose wavelengths were 3 nm spaced, were fabricated and high spectral purity (95% optical power within about 0.6 nm) and wavelength stability were measured. Moreover, the high uniformity of performances across the wafer with different emitted wavelengths demonstrates the maturity of the pro...

Optical Fiber Communication Conference and National Fiber Optic Engineers Conference, 2009

R. Paoletti, Member, IEEE, M. Agresti, D. Bertone, C. Bruschi, S. Codato, C. Coriasso, R. Defranc... more R. Paoletti, Member, IEEE, M. Agresti, D. Bertone, C. Bruschi, S. Codato, C. Coriasso, R. Defranceschi, P. Dellacasa, M. Diloreto, RY Fang, P. Gotta, G. Meneghini, C. Rigo, E. Riva, G.Roggero, A. Stano, M. Meliga, Senior Member, IEEE TTC - Avago Technologies Italy, ...

Thin Solid Films, 1991

... The lattice mismatch was evaluated from the X-ray rocking curve obtained with a double-crysta... more ... The lattice mismatch was evaluated from the X-ray rocking curve obtained with a double-crystal diffractometer. Figure 2 shows the determined energy gaps plotted us. ... Sci. Technol., .3 (1988) 365. I 1 JSA Adelabu, BK Ridley, EG Scott and GJ Davies, Semicond. Sci. ...

Journal of the Optical Society of America B, 1997

Using a widely tunable femtosecond laser source based on an optical parametric amplifier, we perf... more Using a widely tunable femtosecond laser source based on an optical parametric amplifier, we performed pump-probe measurements of the dynamics of the nonlinear transmittance on an InGaAs/InP multiplequantum well sample, with pump and probe beams tuned to the same photon energy as well as with a continuum probe. The pump photon-energy range was 0.8-1 eV. The main results are the following: (i) the ionization time of the n ϭ 1 heavy-hole excitons is 170 fs; (ii) bleaching effects were found to be instantaneous within the temporal resolution of our experiments (50 fs), irrespective of probe photon energy, for excitation within the n ϭ 1 subbands; (iii) the n ϭ 2 to n ϭ 1 intersubband transition time was 1 ps; and (iv) the relative strength of exciton-induced and carrier-induced nonlinearities depends crucially on the photon energy of the probe beam. The transmittance spectra of the multiple-quantum-well system were calculated in the presence of either a cold exciton gas or a quasi-equilibrium carrier plasma. We found that there are conditions in which the ratio of the transmittance variations induced by cold excitons and by thermalized carriers diverges, as experimentally observed.

IEEE Photonics Technology Letters, 1996

Semiconductor integrated waveguide turning mirrors (IWTM) are investigated using the beam propaga... more Semiconductor integrated waveguide turning mirrors (IWTM) are investigated using the beam propagation method. A mirror is fabricated and modeled along with realistic geometries in the presence of offset and roughness of the mirror surface. An interference effect between waves reflected at different surfaces in the device is evidenced, that has strong impact on the device performance in the case of weakly-confining structures. A widely-accepted fabrication approach is criticized in view of this effect. A solution is outlined that minimizes the losses due to either technological limitations or interference.

Applied Physics Letters, 1995

Using an infrared tunable femtosecond source, we investigate the time evolution of exciton absorp... more Using an infrared tunable femtosecond source, we investigate the time evolution of exciton absorption bleaching in InGaAs/InP quantum wells at energies slightly below the exciton absorption peak at room temperature. We find that the bleaching due to photogenerated excitons can be stronger than that due to a thermal electron/hole plasma by a factor of 40. Numerical modeling, based on many‐body theory, yields a qualitative explanation of this unusual behavior, along with its density and spectral dependence as well.

Applied Physics Letters, 1995

... El Mostafa Skouri, Patrick Martin, Laurent Chusseau, Claude Alibert, Claudio Coriasso, Domeni... more ... El Mostafa Skouri, Patrick Martin, Laurent Chusseau, Claude Alibert, Claudio Coriasso, Domenico Campi, Carmelo Cacciatore. Abstract. ... Phys. 77, 1747 (1995). RK Hickernell, DH Christensen, JG Pellegrino, J. Wang, and J.-P. Leburton, J. Appl. Phys. 75, 3056 (1994). ...

Journal of Applied Physics, 2005

We experimentally determine the band offset of strain-compensated InGaAsP-InGaAsP multiquantum-we... more We experimentally determine the band offset of strain-compensated InGaAsP-InGaAsP multiquantum-well (MQW) heterostructures, emitting at 1.55 mum, that were grown by metal-organic chemical vapor deposition. A band offset value of about 56% is found for the conduction band, which is higher than the value reported for the unstrained structure. The temperature dependence of the photoluminescence intensity shows that the unipolar detrapping

High-Power Diode Laser Technology XIX

Proceedings of SPIE - The International Society for Optical Engineering

ABSTRACT

We report both linear and nonlinear grating coupling to a planar multiple quantum well (MQW) wave... more We report both linear and nonlinear grating coupling to a planar multiple quantum well (MQW) waveguide grown by chemical beam epitaxy. We demonstrate a strong dependence of the coupling angle on the incident power in the wavelength range (lambda) equals 1.57 - 1.60 micrometers . The obtained nonlinear variation of neff were found to be negative, and on the order of 10-3, in agreement with many-body calculations performed by the authors. We show that thermal effects can be ruled out. At coupled light intensity as low as 40 mW, nonlinear switching condition was achieved; the power density to obtain the switching process is substantially lower than in previous works. As part of this work, we report the systematic investigation of the linear and nonlinear absorption properties of several InGaAs/InP MQW structures, measuring a series of transmission spectra in the region of the band edge for various pump intensities and observing large changes in the absorption coefficient. Through compa...

Physical Concepts and Materials for Novel Optoelectronic Device Applications II, 1993