We demonstrate a laser tunable in intensity with gigahertz tuning speed based on a III/V reflective semiconductor optical amplifier (RSOA) coupled to a silicon photonic chip. The silicon chip contains a Bragg-based Fabry–Perot resonator to form a passive bandpass filter within its stopband to enable single-mode operation of the laser. We observe a side mode suppression ratio of 43 dB, linewidth of 790 kHz, and an optical output power of 1.65 mW around 1530 nm. We also investigate using a micro-ball lens as an alternative coupling method between the RSOA and the silicon chip.
Real-time dynamic wavelength tuning and intensity modulation of metal-clad nanolasers
To realize ubiquitously used photonic integrated circuits, on-chip nanoscale sources are essential components. Subwavelength nanolasers, especially those based on a metal-clad design, already possess many desirable attributes for an on-chip source such as low thresholds, room-temperature operation and ultra-small footprints accompanied by electromagnetic isolation at pitch sizes down to ∼50 nm. Another valuable characteristic for a source would be control over its emission wavelength and intensity in real-time. Most efforts on tuning/modulation thus far report static changes based on irreversible techniques not suited for high-speed operation. In this study, we demonstrate
- PAR ID:
- 10189691
- Publisher / Repository:
- Optical Society of America
- Date Published:
- Journal Name:
- Optics Express
- Volume:
- 28
- Issue:
- 19
- ISSN:
- 1094-4087; OPEXFF
- Format(s):
- Medium: X Size: Article No. 27346
- Size(s):
- Article No. 27346
- Sponsoring Org:
- National Science Foundation
More Like this
-
more » « less
-
more » « less
Optical isolators, reliably integrated on-chip, are crucial components for a wide range of optical systems and applications. We introduce a new class of wideband nonmagnetic and linear optical isolators based on nonlinear frequency conversion and spectral filtering among the pump, signal, and idler wavelengths. The scheme is experimentally demonstrated using difference-frequency generation in periodically poled thin-film lithium niobate integrated devices and short- and long-pass optical filters. We demonstrate a wide bandwidth of more than 150 nm, limited only by the measurement setup, and an optical isolation ratio of up to 18 dB for the involved idler and signal waves. The difference of transmittance at the signal wavelength between forward and backward propagation is 40 dB. We also discuss pathways for substantial isolation improvement using appropriate anti-reflection coatings. The integrable isolator, operating in the telecommunication band, is characterized by a perfectly linear output versus input power dependence and can be incorporated into high-speed telecom and datacom systems as well as a variety of other applications.
-
more » « less
Here we report a photonic crystal with a split ring unit cell shape that demonstrates an order of magnitude larger peak electric field energy density compared with that of a traditional photonic crystal. Split ring photonic crystals possess several subwavelength tuning parameters, including split ring rotation angle and split width, which can be leveraged to modify light confinement for specific applications. Modifying the split ring’s parameters allows for tuning of the peak electric field energy density in the split by over one order of magnitude and tuning of the air band edge wavelength by nearly 10 nm in the near infrared region. Designed to have highly focused optical energy in an accessible subwavelength gap, the split ring photonic crystal is well suited for applications including optical biosensing, optical trapping, and enhanced emission from a quantum dot or other nanoscale emitter that could be incorporated in the split.
-
more » « less
We present an approach for generating widely separated first sidebands based solely on the four-wave-mixing process in optical parametric oscillators built on complementary metal–oxide–semiconductor-compatible photonic chips. Using higher-order transverse modes to perform dispersion engineering, we obtain zero-group-velocity dispersion near 796 nm. By pumping the chip in the normal dispersion region, at 795.6 nm, we generate a signal field in the visible band (at 546.2 nm) and the corresponding idler field in the telecom band (at 1465.3 nm), corresponding to a frequency span of approximately 346 THz. We show that the spectral position of signal and idler can be tailored by exploiting a delicate balance between second- and fourth-order dispersion terms. Furthermore, we explicitly demonstrate a change in the parametric oscillation dynamics when moving the pump field from the anomalous to normal dispersion, where the chip ceases producing multiple sidebands adjacent to the pump field and generates widely separated single sidebands. This provides a chip-scale platform for generating single-sideband fields separated by more than one octave, covering the visible and telecom spectral regions.
-
Abstract Optically pumped lasing from highly Zn-doped GaAs nanowires lying on an Au film substrate and from Au-coated nanowires has been demonstrated up to room temperature. The conically shaped GaAs nanowires were first coated with a 5 nm thick Al 2 O 3 shell to suppress atmospheric oxidation and band-bending effects. Doping with a high Zn concentration increases both the radiative efficiency and the material gain and leads to lasing up to room temperature. A detailed analysis of the observed lasing behavior, using finite-difference time domain simulations, reveals that the lasing occurs from low loss hybrid modes with predominately photonic character combined with electric field enhancement effects. Achieving low loss lasing from NWs on an Au film and from Au coated nanowires opens new prospects for on-chip integration of nanolasers with new functionalities including electro-optical modulation, conductive shielding, and polarization control.more » « less
