Heterogeneously integrated III-V/silicon dual-mode distributed feedback laser array for terahertz generation

Upraising wavelength exactitude in laser array with spatial hole burning suppression based on the reconstruction-equivalent-chirp technique

An equivalent corrugation pitch modulated distributed-feedback semiconductor multiwavelength laser array (MLA) with two equivalently assisted phase shifts (EAPSs) based on the reconstruction-equivalent-chirp technique is theoretically studied and experimentally demonstrated. The simulated results show that the longitudinal photon density distribution of the studied MLA is much more uniform than that of the MLA without EAPSs. Accordingly, the longitudinal spatial hole burning of the proposed MLA is therefore suppressed more effectively. The experimental results show that the studied MLA has good single-longitudinal-mode performance. The highest side mode suppression ratio (SMSR) is even up to 52.63 dB. Meanwhile, the tunable wavelength range of the investigated MLA is 25.94 nm under the thermal tuning scheme from 15.12°C to 46.93°C. All channels are within a wavelength deviation of  ±0.001n m. The SMSRs are all above 38 dB.

Thermal coupling impact on an MMW carrier generated using two free-running DFB lasers on glass

In this Letter, the impact of thermal coupling between two glass laser cavities on a heterodyned signal for millimeter-wave frequency generation is presented. In addition to a narrow heterodyne linewidth estimated to be lower than 1 kHz, the frequency drift is reduced to ±16.5  ppm/7  s. The signal quality is also evaluated by performing data transmission, respecting communication standards at 60 GHz using complex modulation formats.

On-chip microwave signal generation based on a silicon microring modulator

A photonic-assisted microwave signal generator based on a silicon microring modulator is demonstrated. The microring cavity incorporates an embedded PN junction that enables a microwave signal to modulate the lightwave circling inside. The DC component of the modulated light is trapped in the cavity, while the high-order sideband components are able to exit the cavity and then generate microwave signals at new frequencies in a photodetector. In our proof-of-concept experiment, a 10 GHz microwave signal is converted to a 20 GHz signal in the optical domain with an electrical harmonic suppression ratio of 22 dB. An analytic model is also established to explain the operation mechanism, which agrees well with the measured data.