Monolithically Integrated Temperature Sensor in an InP-based Generic Integration Technology

We have developed various monolithically integrated temperature sensors to locally measure the temperature of InP-based photonic integrated circuits. These sensors are based on InP diodes with either an active multi-quantum well structure or a passive bulk quaternary structure. They have been fabricated in the generic integration process of SMART Photonics. We theoretically and experimentally explored the temperature dependence in the diode characteristics. Our results show that the devices are suitable for on-chip monitoring of the operating temperature of photonic integrated circuits. Integrating a temperature sensor on-chip enables a more local temperature measurement compared to using an external temperature sensor. This should be advantageous for temperature control of photonic integrated circuits

Process control modules for photonic integration technology

High throughput testing for photonic chip

Method for polarization-resolved measurement of electroabsorption

Photonic integrated circuits often use semiconductor components such as amplifiers, detectors, and electroabsorption modulators. For a proper circuit design, it is important to know the absorption spectrum of these semiconductor optical components and how it depends on an applied electric field. We propose a fast and accurate method that uses a compact segmented contact structure to measure the absorption characteristics. The method is based on measuring the transmission of amplified spontaneous emission (ASE) from a single forward-biased section through a varying number of reversely biased absorbing sections. Provided the ASE source emits light in both polarizations, the method measures the absorption spectra for both polarization modes simultaneously, without the need for a polarization filter in the measurement setup

Breaking reciprocity by designed loss

In this paper, we show how designed loss in open quantum systems can break the reciprocity of field propagation, and how non-reciprocal and even unidirectional propagation can be achieved for different kinds of designed loss, both linear and nonlinear. In particular, we show how unidirectional propagation can be achieved for input states of certain symmetry in linear schemes, and demonstrate the possibility of building a single-mode optical insulator by combining two kinds of nonlinear designed losses, and the way to build a non-reciprocal asymmetric field distributor with a planar structure of dissipatively coupled waveguides. We discuss the feasibility of the considered schemes and suggest possible realizations

Fast and robust method for measuring semiconductor optical amplifier gain

\u3cp\u3eIn this paper, we present a new, robust multipoint fitting method for gain measurement with a metric for quality estimation of the procedure. The method is able to identify the deleterious effect of imperfections within the test structures, is tolerant to optical coupling errors and is well suited to high throughput, generic, automated testing of semiconductor optical amplifiers. Gain is estimated in a range of pump current densities over multiple spectral bands from 1400 to 1600 nm with a standard error in the order of 1/cm.\u3c/p\u3

Characterization of distributed bragg reflectors using optical frequency domain reflectometry

We present a novel and accurate method for characterizing the reflection spectra of distributed Bragg reflectors (DBRs) using the optical frequency domain reflectometry (OFDR) method. A compact test structure with integrated reference mirror and photodetector is designed to overcome the dependence on the fiber coupling

OpenEPDA: photonic PDKs with open standards

When creating photonic integrated circuits, designers use CAD tools and the Process Design Kits (PDK) for the selected technology. Currently, providing and supporting a PDK for multiple design tools requires a lot of effort and is error-prone due to absence of any standard workflow for this process. Most often a foundry has independent PDK support teams for each design tool. We are addressing the problem of PDK creation and validation by introducing a standardized PDK representation. In this representation, PDK constitutes is a single dataset, which is software-independent and is provided by the foundry. It can be imported and compiled into a software-dependent PDK (library, package, etc.) to be used for desired design tool.openEPDA provides a set of standards for such PDK representation. Additionally, it implements several tools for PDK validation, both online and offline.The proposed approach was tested and confirmed in the JePPIX Pilot Line project (https://www.jeppix.eu/jeppix-pilot-line-in-a-nutshell/) with three foundries and four EPDA tool vendors