Over the past five years, Switzerland has undergone major changes in the field of photonics. Thanks to a well-positioned photonics industry and dedicated professional associations, new milestones were set in the area of training and further education, but also in research and development.
The main reason for the shortage of skilled workers in Switzerland was identified as the lack of education for qualified photonics engineers at bachelor and master level. Some years ago, the majority of the Swiss photonics companies syndicated under the patronage of Swissmem as its Photonics Division. In 2015 the members defined their requirements for young skilled workers and prepared a position paper "Bachelor in Photonics" in which Universities of Applied Sciences (UAS) were specifically asked to offer application-oriented bachelor programs.
The NTB with its long tradition in photonics R&D decided to go for such a program. A team developed a curriculum for a photonics profile and implemented it as part of the “Bachelor in Systems Engineering”. In autumn 2018 the first bachelor students graduated in photonics and were ready for an industrial career. The next step on the education roadmap in Switzerland was a specific profile in photonics as part of a nationwide Master Program in Engineering (MSE) for bachelor graduates of UAS. Here again the momentum came from the Swiss photonics industry. The planning and implementation of this unique master program is currently underway and is scheduled to start in September 2020.
An integrated optical displacement sensor based on a reflective Mach–Zehnder interferometer (MZI) was developed. The sensor features a low-loss autocollimation measurement head fabricated using a 62.5-μm gradient index fiber as lens, which separates the incoming and reflected light. The mounting of the lenses and the fiber coupling were performed using a passive alignment assembly technology. Using a 3 × 3 directional coupler (DC), the direction of the phase shift can be resolved. The measurement head exhibits low losses compared to a conventional DC to separate the reflected light. A measurement range of 225 μm could be achieved in good agreement with the expected 230 μm. The results show a good agreement between simulation and measurements. Using basic measurement electronics, movements of 2 nm can be resolved, while a resolution of <1 nm is expected using optimized measurement equipment.
In this investigation the influence of the local environment on the laser damage threshold of anti-reflective coatings is
reported. For this purpose, HfO2 / SiO2 anti-reflective coatings were deposited on fused silica substrates using an ionbeam
sputter system. Laser damage threshold measurements were performed using two test procedures, S-on-1 and Ron-
1, at 355 nm for temperatures ranging from room temperature up to 250 °C and in different atmospheres. The two
test procedures had comparable LIDT results with a possible pre-conditioning effect evidenced by a broadening of the
transition range of the R-on-1 measured samples. It was found that samples measured in normal atmospheric air showed
superior laser resistance compared to samples measured under nitrogen purge or in dry air. Samples measured in normal
atmospheric air also showed a temperature dependence with an improved laser resistance at 25 °C. No temperature
dependence was observed for samples measured under nitrogen purge or in dry air. In this paper, literature showing
similar effects is reviewed and the influence of a water epilayer on the coating as a possible cause for the observed
results is discussed.
A silicon device to simplify the coupling of multiple single-mode fibers to embedded single-mode waveguides has been developed. The silicon device features alignment structures that enable a passive alignment of fibers to integrated waveguides. For passive alignment, precisely machined V-grooves on a silicon device are used and the planar lightwave circuit board features high-precision structures acting as a mechanical stop. The approach has been tested for up to eight fiber-to-waveguide connections. The alignment approach, the design, and the fabrication of the silicon device as well as the assembly process are presented. The characterization of the fiber-to-waveguide link reveals total coupling losses of (0.45±0.20 dB) per coupling interface, which is significantly lower than the values reported in earlier works. Subsequent climate tests reveal that the coupling losses remain stable during thermal cycling but increases significantly during an 85°C/85 Rh-test. All applied fabrication and bonding steps have been performed using standard MOEMS fabrication and packaging processes.
Optical coatings used in ultraviolet applications are often exposed to harsh environments operating at elevated temperatures. In order to study the impact of the ageing effects optical coatings experience at various operating temperatures, an ultraviolet laser-induced degradation test system has been developed. It allows for flexible use in both a long-term stability test bench as well as in an LIDT measurement system. This work contains the preliminary results of optical degradation tests at 355 nm performed on anti-reflective coatings. As a subsequent step, the LIDT of the samples were measured using a Q-Switched Nd:YAG laser operating at 1064nm.
Thermo-optical switches are widely used in integrated optics and various types of integrated optical structures have been reported in literature. These structures include, but are not limited to Mach-Zehnder-Interferometer (MZI) switches and digital optical switches. The thermo-optical effect depends on the refractive index, the polarizability and the density of a material. The polarizability effect can often be neglected and the change of refractive index is dominated by a density change due to the thermal expansion of the material.
We report herein a new method to measure the thermo-optical effect of waveguides directly, using integrated MZIs fabricated in polymer waveguide technology. Common methods rely on macroscopic samples, but the properties can differ significantly for micro-structured waveguides. Using a floodlight halogen rod lamp and metal-shields, we realized a radiation heater with a trapezoidal-shaped heating pattern. While the heating occurred from the bottom side, a thermocouple was placed on top of the sample. By dynamically measuring the temperature and the corresponding output-power of the MZI, the temperature difference between constructive and destructive interference can be determined. Multiple measurements of different sample MZIs exhibit an average thermo-optical coefficient (TOC) of 1.6 ∗ 10-4 1/K .
Manufacturing processes from the private and academic sectors were used to deposit anti-reflective and high-reflective coatings composed of Ta2O5 - SiO2 multilayers. Used deposition techniques included three Ion Assisted Deposition (IAD) systems and an Ion Beam Sputtering (IBS) system. Coatings were performed on fused silica (Corning 7980) substrates polished by two different suppliers. LIDT Measurements were performed using a Q-Switched Nd:YAG laser operating at 1064nm. The paper presents a comparison of the coatings in terms of laser damage threshold values, optical properties and surface quality.
The increasing demand for planar polymer optical waveguides integrated into electrical printed circuit boards (PCB)
calls for mass production capabilities: Hence, appropriate materials, systems, assembly concepts and production
technologies become vital, in order to guarantee a high reproducibility and quality of the waveguides. The manufacturing
and assembly costs have to be kept on a low level, while the integration of the highly sensible waveguides into the rough
environment of PCB's with their cheap and non-ideal substrates is a particular challenge.
The present paper describes an assembly and manufacturing technology for electro-optical circuit boards which meets
these requirements.
First, the manufacturing and characterization of multimode polymer waveguides is presented and the process for layer
deposition and structuring is described. Specific attention is given to the reproducibility of these processes ensuring the
high optical quality of the waveguides. Additionally, some problems arising from the integration of the waveguides into
the PCB's are discussed.
Second, various light coupling concepts are presented. In particular, a novel mirror element based on parabolic reflectors
is described. The optical design was calculated analytically and optimized using computer simulations. The mirror
element was fabricated using injection molding in a reproducible manner at high quantities and lowest cost.
To allow for a wider tolerance in the subsequent assembly steps our novel electro-optical transceivers concept facilitates
the use of conventional SMD- placement machines for mounting which makes the process very cost effective. This
concept was demonstrated successfully and is also described within the third section.
In the last part the practical use of this building set is illustrated with different successfully realized applications in the
field of ICT and optical sensor technology.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.