1300 nm Semiconductor Optical Amplifier Compatible With an InP Monolithic Active/Passive Integration Technology

Abstract

In monolithic photonic integrated circuits (PICs), an optimized active/passive integration is needed to provide efficient coupling and low amount of interface reflections between amplifiers and passive components. A 1300 nm semiconductor optical amplifier (SOA) on InP substrate and optimized for butt-joint reflections is investigated. Material performance were assessed from measurements of broad area lasers. Room temperature operation reveals 1.2 W single facet output power with threshold current around 100 A/cm 2 per well. Characteristic temperatures of T0=75 K and T1=294 K were obtained. A compact model description of the SOA, suitable for the design of PICs and rate equation analysis, was applied to parametrize the unsaturated gain measurements. Current injection efficiency of 0.65, transparency carrier density of 0.57 10 18 cm -3 , and free carrier absorption losses up to 15 cm -1 were extracted from fitting the data. The model is verified with measurements of optical gain saturation. A modal gain of 15 dB for a 600 µm long narrow ridge SOA leads to output saturation power higher than 30 mW at 7 kA/cm 2 . This building block contributes to the development of an InP monolithic integration technology in the 1300 nm range, which can enable the use of photonic integrated circuits in many kind of applications.

Two-section passively Mode-locked laser as a test for amplification and absorption parameters of a quantum well based InP optical amplifier at 1300 nm

“…This expression has been experimentally validated on the active layer stack used in this laser design with the modal gain measurement described in [22]. The wavelength independent parameters in this model 𝛾, 𝜒 and 𝑁 0 have been determined from fitting to modal gain measurements as well as the relation between the bandgap frequency 𝑓 0 and the carrier density N, as explained in detail in [5]. The modal gain is then calculated including a parametrization of the amplifier free carrier losses.…”

“…On the basis of such compact models it is possible to develop simulation tools for more complex laser systems that can be realized on active/passive integration platforms such as those on InP [3], [4]. A compact model of a new quantum well based amplifier at 1300 nm suitable for an active passive butt joint integration technology has been reported by us [5]. This model has now been used to describe a two-section passively mode-locked laser and in that way to test the parameters of the compact model.…”

Design and Analysis of Novel O-Band Low Polarization Sensitive SOA Co-Integrated With Passive Waveguides for Optical Systems

“…1(a)) and along the light propagation (Fig. 1(b)) of the designed shallow waveguide SOA with a 2 μm width, and two shallow passive waveguides co-integrated through monolithically coupling in a so-called butt-joint integration process [15][16][17][18][19][20][21][22]. The three shallow ridges are separated from each other by a trench, as the fabricated device should be.…”

“…Based on this design, the 2 μm width passive shallow waveguides have a loss lower than 2 dB/cm and details of the passive waveguide design can be found in Ref. [21]. Figure 1(c) shows the schematic top view of the SOAs with three different lengths co-integrated with passive waveguides.…”

“…The refractive index variation from active to passive waveguides is very low and thus we expect lower reflection and loss. Previous experimental results show that the resulting co-integration for C-and O-band activepassive coupling shows negligible reflections less than 9×10 -5 and low coupling losses (< 0.2 dB) [15], [19][20][21]. Since the reflection is very negligible, in order of 10 -5 (because of very good refractive matching of the passive and active waveguide), thus the ripples in the amplified spontaneous emission (ASE) do not appear.…”