InAs/InP (100) quantum dots in InP photonic integrated laser systems

Geen abstrac

InAs/InP (100) quantum dots in InP photonic integrated laser systems

Geen abstrac

Investigation into diode pumped modelocked ND based laser oscillators for the CLIC photoinjector system

The photo-injector system envisaged for the proposed CLIC linear e+-e- accelerator at CERN has a demanding set of specifications on output pulse structure, power and timing stability. This paper reports on results obtained with quasi-CW diode pumped laser oscillators with output stabilisation. A 300W 804nm diode array stack is used to side pump Nd:YLF (1047nm) crystals with 200μs pulses at 100Hz repetition rate. Using feedback from the laser output to control an acousto-optic loss modulator in the cavity, start-up spiking and Q-switched behaviour is suppressed. Preliminary results obtained on incorporation of a saturable absorbing mirror for passive modelocking are presented

Widely tunable laser source for gas sensing applications

In gas detection systems based on a single absorption line, wide-range, precision-tunable, continuous-wave laser sources are desired in order to allow for accurate targeting and measuring absorption profiles of particular gas species. A widely tunable ring laser using an intra-cavity wavelength tuning mechanism based on asymmetric Mach-Zehnder interferometers has been realized in the form of a monolithic indium phosphide photonic integrated circuit following a generic photonic integration approach. Furthermore, such integration technology enables the possibility of a co-integration of multiple lasers on a single photonic chip and allowing a gas detection system to monitor a few gas species simultaneously

Integrated extended-cavity 1.5-μm semiconductor laser switchable between self- and anti-colliding pulse passive mode-locking configuration

We present the first integrated linear extended-cavity passively mode-locked (PML) semiconductor laser in which the operating mode can be switched electrically between two configurations. The first configuration is where the saturable absorber (SA) is located next to the output coupler, the so-called anti-colliding pulse mode-locking (ACPML) scheme. The second is where the SA is next to the high reflectance mirror, the self-colliding pulse mode-locking (SCPML) scheme. The 7.5-GHz PML was used to demonstrate experimentally the theoretical prediction that placing the SA next to the output coupler leads to a significant improvement in the laser stability and quality of the optical pulses. The experimental results show that the ACPML scheme allows for more deeply saturated SA due to the increase of optical power in the SA. The measurements of the RF spectra and autocorrelation traces confirm the superiority of the ACPML design in terms of pulse stability and width over the SCPML design for a wide range of operating conditions. The linewidth of the beat tone at the repetition rate was reduced by more than 60 times, the measured minimal autocorrelation width improved from 22 to 7.5 ps and a 3 dB increase in average output power was achieved

Design of feedback insensitive InP ring laser

The optical isolators used to protect semiconductor lasers against optical feedback cannot be integrated. Therefore we propose to fabricate a laser that has a strongly reduced sensitivity to feedback. Simulations show that such a device can be realized by employing a ring laser in which the clockwise and counterclockwise modes are not coupled. To achieve unidirectional lasing, this work proposes to use an intra cavity weak optical isolator based on two phase modulators that are driven 90 degrees out of phase. Simulations show up to 3% of intensity feedback can be tolerated without any distinguishable effect on the laser light

Characterization of integrated electro-optically tunable cascaded filters for tunable laser purposes

In this contribution we present our results on the tunable arrayed waveguide gratings designed and fabricated to be used in a tunable ring laser structure in the 1600 to 1800nm range. To be able to tune the two cascaded filters over 100 to 200nm the wavelength dependent phase shifting in the phase shifters have been measured. With the knowledge of the wavelength dependency in the phase shifters we are able to tune the AWG over the full wavelength range