Peidong Wang

Half-symmetric cavity tunable microelectromechanical VCSEL with single spatial mode

A new class of microelectromechanically tunable vertical-cavity surface-emitting lasers with a half-symmetric cavity structure is described. The cavity is realized by inducing a curvature (R/spl sim/320 /spl mu/m) in the top movable dielectric mirror. The microcavity forces lasing oscillations in a single fundamental spatial mode of approximately 6 /spl mu/m despite the 20 /spl mu/m electrical aperture of the device. The device wavelength was tunable from 863 to 833 nm under a 13-V voltage swing. The device operates in a single fundamental mode with sidemode supression ratio of >20 dB throughout the tuning range.

Widely tunable Fabry-Perot filter using Ga(Al)As-AlO x deformable mirrors

A microelectromechanically tunable Fabry-Perot (FP) microinterferometer is demonstrated using Ga(Al)As-AlO/sub x/ DBR micromirrors separated by an air gap. The broad-spectral response of Ga(Al)As-AlO/sub x/ distributed Bragg reflector (DBR) micromirrors allows 3-dB bandwidth of the cavity to remain narrow and stable over the tuning range. Two devices with different number of mirror structures were demonstrated exhibiting linewidths of 0.5 and 2.0 nm, tuning ranges of 59 and 83 nm, respectively. In addition to a fundamental FP spatial mode, we also observe higher order spatial modes that we associate with a lensing effect caused by partially oxidized AlGaAs layers within the mirror layers.

MEMs-Tunable vertical-cavity surface-emitting lasers

We present a MEM-VCSEL which can provide over 50 nm of wavelength tuning, up to 8 dBm optical power, and a high side mode suppression. The viability of these devices for telecom applications is directly demonstrated through transmission experiments.

C-band tunable 6 mW vertical-cavity surface-emitting lasers

We demonstrate micro-electromechanical vertical-cavity surface-emitting lasers (MEM-VCSELs) that couple >6 mW of power into a single-mode fiber. These devices are continuously tunable across the entire c-band and offer error-free transmission over >500 km of single-mode fiber at OC-48 data rates.

Half-symmetric cavity microelectromechanically tunable vertical cavity surface emitting lasers with single spatial mode operating near 950 nm

We describe tunable vertical cavity surface emitting lasers with a half-symmetric cavity structure. The cavity is realized by inducing a curvature (R∼300 μm) in the top movable dielectric mirror. This half-symmetric microcavity forces lasing oscillations in a single fundamental spatial mode with a side-mode suppression ratio of >25 dB. Continuous wavelength tuning of 44 nm was achieved microelectromechanically with a tuning voltage of 14 V. The device operates near 950 nm with maximum power output of ∼0.9 mW.

Widely tunable Fabry-Perot filters using high-index-contrast DBRs

Realization of microelectromechanically wavelength tunable Fabry-Perot filters using high index-contrast distributed Bragg reflectors (DBRs) comprising GaAlAs/AlOx and Si/SiO2 material system are reported. Due to the broadband nature of these high index-contrast DBRs, the 3dB transmission bandwidth of the cavity resonance is narrow and stable over the tuning range. While the three different sets of GaAlAs/AlOx based filters with different number of DBRs exhibited linewidths of 0.5nm, 2.0nm and 0.47nm with tuning ranges of 59nm, 83nm, and 60nm respectively, the silicon-based filter exhibited a linewidth of 0.3nm and a tuning range of 12nm. Transmission spectra from these devices displayed varying magnitudes of higher order spatial modes were attributed to lensing effect caused by partially oxidized AlGaAs layers within the mirror layers. One of the GaAlAs filters showed a frequency response of 500 KHz at 3dB cutoff point indicating a switching time of 2 microseconds.

Error free 2.5 Gb/s transmission over 125 km conventional fiber of a directly modulated widely tunable vertical cavity surface emitting laser

A vertical cavity surface emitting laser with over 35 nm tuning range is modulated through its optical pumping at rates up to 2.5 Gb/s. Error free transmission is obtained for a conventional fiber of 125 km.

Widely tunable Fabry-Perot filter using Ga(Al)As/AlO/sub x/ deformable mirrors

Summary form only given. Microelectromechanical filters with FWHM linewidth of 0.47 nm and over 70-nm tuning was demonstrated with <1 dB insertion loss. The filters maintain their characteristics throughout the tuning range. Furthermore, the high frequency operation of such filters was established. The 3 dB cutoff frequency of 500 kHz was recorded.