Thick film hydrogen silsesquioxane planarization for passive component technology associated with electronic-photonic integrated circuits.

A novel AlGaInAs/InP electro-absorption modulated laser (EML) with a simple fabrication process is proposed, in which the electro-absorption modulator (EAM) has a 10 nm blueshift induced by quantum well intermixing (QWI) and is monolithically integrated with a sidewall grating distributed-feedback (DFB) laser working at 1.55 μm wavelength. The extent of the QWI process is characterized by a diffusion length. The quantum confined Stark effect (QCSE) is simulated in terms of extinction ratio (ER) and chirp for bias electric fields from 0 kV/cm to 200 kV/cm and for different amounts of intermixing. The results indicate that for a 150 µm-long EAM with a 10 nm blueshift induced by QWI, an ER of 40 dB is obtained at 2.5 V reverse bias with no penalty in chirp compared to an as-grown quantum well (QW) and the insertion loss at 0 V bias is 0.11 dB for 1.55 µm operation wavelength. The simulated –3 dB bandwidth of the electrical to optical power response is 22 GHz.

We present a new electroabsorption modulated laser based on a lumped configuration, identical epitaxial layer scheme, and a new low-permittivity planarization method. The design of the device is intended to offer a high modulation frequency using a simple and cheap fabrication process. A thick-film of HSQ spinon coating was used to planarize the device and enable a low capacitance contact to the p-side. A 6-µm-thick planarized HSQ layer was fabricated and used to implement the electrode to the electroabsorption modulator.

achieving optimized interface matching between the microwave and photonic signals. The device used an AlGaInAs/InP p-in structure containing 5 Quantum Wells (QWs). AlGaInAs based QWs have a larger conduction band discontinuity and smaller valence band discontinuity compared to the more conventional InGaAsP system. This property provides higher electron confinement and a higher characteristic temperature for lasers, making the material system attractive for uncooled laser operation and improving EAM performance [1], [2].

We present an electroabsorption modulated laser based on an identical epitaxial scheme, side-wall grating, on-chip microwave probe interface, and a new low-permittivity planarization method. The modulation speed is significantly increased by reducing the electrode capacitance by planarizing with a 5-µm-thick HSQ layer. Furthermore, implementing the electrode with a direct ground-signal-ground probe interface provides a straightforward interconnection that obviates the need for an external circuit and bonding wires. The device operates at 1565 nm wavelength with stable single-mode lasing, no modehopping, and a side mode suppression ratio above 35 dB. An extinction ratio of 19.5 dB was recorded at the maximum modulator bias of −4 V. The electrical to optical power response of the modulated signal at -3-dBo demonstrated a 19 GHz bandwidth at an extinction ratio of 7 dB, which supports error-free data transmission up to 27 Gbit/s.