RESUMEN
Two twelve-channel arrays based on surface-etched slot gratings, one with non-uniformly spaced slots and another with uniformly spaced slots are presented for laser operation in the O-band. A wavelength tuning range greater than 40 nm, with a side-mode suppression ratio (SMSR) > 40 dB over much of this range and output power greater than 20 mW, was obtained for the array with non-uniform slots over a temperature range of 15 °C - 60 °C. The introduction of multiple slot periods, chosen such that there is minimal overlap among the side reflection peaks, is employed to suppress modes lasing one free spectral range (FSR) from the intended wavelength. The tuning range of the array with uniformly spaced slots, on the other hand, was found to be discontinuous due to mode-hopping to modes one FSR away from the intended lasing mode which are not adequately suppressed. Spectral linewidth was found to vary across devices with the lowest measured linewidths in the range of 2 MHz to 4 MHz.
RESUMEN
Spectral engineering has been demonstrated for the circular-side square microlasers with an output waveguide butt-coupled to one vertex. By carefully optimizing deformation parameter and waveguide connection angle, undesired high-order transverse modes are suppressed while the mode Q factors and the transverse-mode intervals are enhanced simultaneously for the low-order transverse modes. Dual-mode lasing with pure lasing spectra is realized experimentally for the circular-side square microlasers with side lengths of 16 µm, and the transverse mode intervals can be adjusted from 0.54 to 5.4 nm by changing the deformation parameter. Due to the enhanced mode confinement, single-mode lasing with a side-mode suppression-ratio of 36 dB is achieved for a 10µm-side-length circular-side square microlaser with a 1.5µm-wide waveguide.
RESUMEN
A compact, simple, and bistable hybrid square-rectangular laser is experimentally demonstrated as an all-optical flip-flop memory. Controllable bistability is induced by two-mode competition, together with the saturable absorption at the square microcavity section. The all-optical set and reset operations are realized by injecting signal pulses at two-mode wavelengths, with the response times of 165 and 60 ps at the triggering pulse width of 100 ps and switching energies of 2.7 and 14.2 fJ, respectively. The robust hybrid-cavity design has an active area of 660 µm2 and permits efficient unidirectional single-mode lasing, low-power flip-flop operation, and superior fabrication tolerance for monolithic photonic integration.
RESUMEN
A simple dual-loop optoelectronic oscillator using a 16 µm side length AlGaInAs/InP directly modulated microsquare laser is proposed and investigated without an external modulator. High-performance first harmonics are realized, with 3 dB linewidth, less than 200 Hz, and a frequency-tunable range from 2 to 8 GHz. Meanwhile, a side-mode suppression ratio of 60 dB is obtained for the microwave by the dual-loop structure. Within the whole tuning range, the measured single-sideband phase noises of the first harmonics are about -110 dBc/Hz at 10 kHz frequency offset. Furthermore, the second and third harmonics with frequency-tunable ranges from 4 to 16 GHz and 6 to 24 GHz are achieved as well.
RESUMEN
We propose and demonstrate a locally deformed-ring (LDR) hybrid microlaser to realize stable unidirectional emission from a silicon waveguide. The coupled modes eliminate the competition between clockwise (CW) and counter-clockwise (CCW) modes, and the highly unidirectional characteristics are achieved with an enhanced mode quality factor based on a locally deformed notch in the LDR resonator. Using a divinylsiloxane-benzocyclobutene bonding technique, a LDR hybrid microlaser is fabricated vertically coupled to a silicon waveguide with a radius of 20 µm, a ring width of 4 µm and a notch width of 500 nm. The threshold current is 7 mA, and single-mode lasing is achieved with the side-mode suppression ratio of 27 dB. Nearly total unidirectional output from the CCW direction of a Si waveguide is demonstrated with a unidirectional ratio of 0.053.
RESUMEN
An effective method for multicoherence wavelength generation is experimentally demonstrated using an integrated twin-microdisk laser as a seeding source. Dual-wavelength lasing with variable wavelength spacing is achieved by adjusting injection currents independently. Using the integrated laser as a pump seed, we obtain multicoherence wavelength in a nonlinear optical fiber, which has a tunable frequency interval from 50 to 300 GHz. Ten waves with optical signal to noise ratio from 28 to 10 dB are produced at the frequency interval of 200 GHz and a pulse width of 1.2 ps. The high extinction ratio of the pulse trace indicates the high coherence in the mode-locked multiwavelength light source.
RESUMEN
Narrow-linewidth and low phase noise photonic microwave generation under sideband-injection locking are demonstrated using an 8-µm-radius AlGaInAs/InP microdisk laser subject to optical injection and optoelectronic feedback. Microdisk laser subject to external optical injection at the period-one state provides the microwave subcarrier seed signal, and the optoelectronic feedback serves as direct current modulation to stabilize and lock the generated microwave signal without using the electrical filter. High-quality photonic microwave signals are realized with the 3-dB linewidth of less than 1 kHz and the frequency tunable range from 8.8 to 17 GHz. Single sideband phase noise of -101 dBc/Hz is obtained at a frequency offset of 10 kHz for the generated 14.7 GHz signal. Furthermore, the dependences of photonic microwave signal on the optical injection and optoelectronic feedback parameters are investigated.