Field-induced guide/antiguide modulators on InGaAsP/InP (original) (raw)
Related papers
Etched beam splitters in InP/InGaAsP
Optics Express, 2011
An etched beam splitter (EBS) photonic coupler based on frustrated total internal reflection (FTIR) is designed, fabricated and characterized in the InP/InGaAsP material system. The EBS offers an ultra compact footprint (8x11 μm) and a complete range of bar/cross coupling ratio designs. A novel pre-etching process is developed to achieve sufficient depth of the etched coupling gaps. Fabricated EBS couplers demonstrate insertion loss between 1 and 2.6 dB with transmission (cross-coupling) 10%. The results show excellent agreement with 3D finite-difference timedomain (FDTD) modeling. The coupling of EBS has weak wavelength dependence in the C-band, making it suitable for wavelength division multiplexing (WDM) or other wide bandwidth applications. Finally, the EBS is integrated with active semiconductor optical amplifier (SOA) and phase-modulator components; using a flattened ring resonator structure, a channelizing filter tunable in both amplitude and center frequency is demonstrated, as well as an EBS coupled ring laser.
Deep dry etching process development for photonic crystals in InP-based planar waveguides
Photonic Crystal Materials and Nanostructures, 2004
Chlorine-based inductively coupled plasma etching processes are investigated for the purpose of etching twodimensional photonic crystals in InP-based materials. Etch rates up to 3.7 m/min and selectivity's to the SiN mask up to 19 are reported. For the removal of indiumchloride etch products both the application of elevated temperatures and high ion energy's are investigated. The reactor pressure is an important parameter, as it determines the supply of reactive chlorine. It is shown, that N 2 passivates feature sidewalls during etching, improving the anisotropy. Ions that impact onto the sidewalls, either directly or after scattering with the SiN-mask or hole interior, cause sidewall etching. Highly directional ion bombardment and vertical sidewalls in the SiN-mask are therefore crucial for successful etching of fine high aspect ratio structures.
InP-based waveguides: comparison of ECR plasma etching and wet-chemical etching
Acta Metallurgica Et Materialia, 2000
Electron Cyclotron Resonance (ECR) reactive ion etching of InP-based waveguide structures was studied using CH4/H2/Ar chemistry. The ECR process was first optimized on InP substrates before being used to process waveguides. Stripes of 2 µm width were patterned in silicon nitride and used as masking to etch strip-loaded waveguides. These waveguides were compared with wet-etched waveguides, in order to identify the dominant loss mechanism. Fabry-Perot loss measurements showed values as low as 1.1 dB/cm for the ECR-etched waveguides. From the comparison it appears that roughness of the sidewalls is more important than surface damage for the loss of these waveguides.
Low-Loss InGaAsP/InP Surface Ridge Waveguides for Photonic Integrated Circuits
IEEE Photonics Technology Letters, 2016
We demonstrate low-loss InGaAsP/InP surface ridge waveguides with loss as low as 0.81 dB/cm measured at 1550 nm for the fundamental TE mode. These waveguides are suitable for monolithic integration with active elements in InP-based Photonic Integrated Circuits. We study the effect of proton-implantation on waveguide loss for different ridge widths.
Optics Express, 2008
A novel structure, namely a laterally tapered undercut active-waveguide (LTUAWG) for an optical spot-size converter (SSC) is proposed and demonstrated in this paper. Using a selectively undercut-etching-active-region (UEAR) on a laterally tapered ridge to define a LTUAWG, a vertical waveguide directional coupler (VWGDC) can be fabricated simply by a wet etching-based technique. The VWGDC comprises a top LTUAWG and a bottom passive waveguide (PWG). An electroabsorption modulator (EAM) is monolithically integrated with a LTUAWG-VWGDC serving as the connecting active waveguide (AWG) and the optical transmission testing device. Through a loss budget analysis on an EAM-integrated VWGDC, an optical mode transfer loss of-1.6 dB is observed between the PWG and the AWG. By comparing the reverse directions of optical excitation, the identical optical transmission relations with bias are observed, further verifying the high efficiency properties in a SSC. Optical misalignment tolerance is employed to test the two transferred optical modes. 1dB misalignment tolerance of ±2.9 μm (horizontal) and ±2.2 μm (vertical) is obtained from the PWG, which is better than the value of ±1.9 μm (horizontal) and ±1.6 μm (vertical) from the AWG. Far-field angle measurement shows 6.0 ο (horizontal) × 9.3 ο (vertical) and 11 ο (horizontal) × 20 ο (vertical) for the PWG and the AWG, respectively, exhibiting the capability of a mode transformer. All of these measurements are also examined by a 3D beam propagation method (BPM) showing quite consistent results. In this wet etching technique, no regrowth is needed during processing. Furthermore, UEAR processing controlled by in situ monitoring can lead to a simple way for submicron-size processing, showing that a highly reliable processing technique can thus be expected. A low cost of fabrication can also be realized, indicating that this method can be potentially used in optoelectronic integration.
Novel postetch process to realize high quality photonic crystals in InP
Thermally driven reflow of material during annealing was positively used to obtain near-vertical sidewall profiles for high-aspect-ratio nanostructures in InP fabricated by dry etching. This is very promising for achieving high optical quality in photonic crystal ͑PhC͒ components. Nearly cylindrical profiles were obtained for high-aspect-ratio PhC holes with diameters as small as 200-350 nm. Mini stop bands ͑MSBs͒ in line-defect PhC waveguides were experimentally investigated for both as-etched and reshaped hole geometries, and their spectral characteristics were used to assess the quality of PhC fabrication. The spectral characteristics of the MSB in PhC waveguides with reshaped holes showed significant improvement in performance with a transmission dip as deep as 35 dB with sharp edges dropping in intensity more than 30 dB for ϳ4 nm of wavelength change. These results show potential for using high extinction drop-filters in InP-based monolithic photonic integrated circuit applications. Finally, it is proposed that other nanostructure geometries may also benefit from this reshaping process.
Photonic integration for high-denisty and multifunctionality in the InP-material system
Optoelectronic Integrated Circuits VIII, 2006
Monolithic photonic integration offers unsurpassed perspectives for higher functional density, new functions, high performance, and reduced cost for the telecommunication. Advanced local material growth techniques and the emerging photonic crystal (PhC) technology are enabling concepts towards high-density photonic integration, unprecedented performance, multi-functionality, and ultimately optical systems-on-a-chip. In this paper, we present our achievements in photonic integration applied to the fabrication of InP-based mode-locked laser diodes capable of generating optical pulses with sub-ps duration using the heterogeneous growth of a new uni-traveling carrier ultrafast absorber. The results are compared to simulations performed using a distributed model including intra-cavity reflections at the sections interfaces and hybrid mode-locking. We also discuss our work on InP-based photonic crystals (PhCs) for dense photonic integration. A combination of two-dimensional modeling for functional optimization and three-dimensional simulation for real-world verification is used. The fabricated structures feature more than 3.5µm deep holes as well as excellent pattern-transfer accuracy using electron-beam lithography and advanced proximity-effects correction. Passive devices such as waveguides, 60° bends and power splitters are characterized by means of the end-fire technique. The devices are also investigated using scanning-near field optical microscopy. The PhC activity is extended to the investigation of TM bandgaps for all-optical switches relying on intersubband transitions at 1.55µm in AlAsSb/InGaAs quantum wells.