Uncovering the formation history of dusty star-forming galaxies in the early universe requires wideband spectroscopic instruments capable of detecting redshifted emission lines in the millimeter and submillimeter regime. The on-chip spectrometer DESHIMA 2.0 addresses this by integrating filterbanks and kinetic inductance detectors (KIDs) onto a single chip, enabling wide frequency coverage in a compact footprint. However, performance is currently limited by losses in the dielectric layer of its microstrip lines, which reduce transmission efficiency and sensitivity. Minimizing these losses is crucial not only to enhance signal throughput but also to enable the use of parallel-plate capacitors (PPCs), which significantly reduce resonator size, increase detector count, and thus improve spectral resolution. Achieving low-loss dielectric films is therefore essential for the next generation of high-resolution spectrometers such as TIFUUN.

To support this development, this thesis focuses on optimizing the deposition of hydrogenated amorphous silicon (a-Si:H) films using Inductively Coupled Plasma Enhanced Chemical Vapor Deposition (ICP-CVD). These films function as dielectric layers in both microstrip lines forming the filterbank (90–360 GHz) and in PPCs (1–10 GHz).

Since direct measurement of dielectric losses was beyond the scope of this project, optimization was based on properties known to correlate with loss mechanisms—namely two-level systems (TLSs) and absorption in the vibrational tail. TLSs are expected to dominate at PPC operating frequencies, while vibrational absorption is more relevant in the filterbank. The optimized properties include residual stress, thickness non-uniformity, optical and infrared refractive index, band gap, void-volume fraction, hydrogen content, and microstructure parameter.

A Taguchi L18 orthogonal array was used to systematically vary seven deposition parameters: table temperature, silane flow rate, ICP power, table RF power, gas ratio (silane/argon), pressure, and native oxide removal method (argon milling vs HF dip). Film properties were evaluated using ellipsometry, FTIR spectroscopy, and a stressmeter.

ANOVA revealed table RF power as the dominant factor, with the highest contribution to five of the eight properties: thickness uniformity, refractive index, hydrogen content, microstructure, and residual stress. In the latter, increasing power shifted the film from tensile to strongly compressive regimes. Other parameters had more moderate effects: chamber pressure had strongest influence on void-volume fraction and infrared index, while silane flow rate and wafer preparation affected the band gap most significantly. Despite some models exhibiting high residuals, indicating unmodeled interactions between the parameters, the overall analysis successfully identified key relationships between the deposition parameters and the material properties.

Two optimized recipes were selected using Grey Relational Analysis, with equal weighting assigneds to hydrogen content and void-related properties. Recipe 19 achieved minimal hydrogen content (4.3 at.%) and low residual stress, making it a strong candidate for minimizing dielectric losses in the filterbank. However, it also showed high void fraction and surface inhomogeneity. Recipe 20, aimed at maximizing hydrogen content, reached 16.3 at.% but showed only average performance and suffered from high compressive stress (–745 MPa). As a more robust alternative, Recipe 9 offered low void content, moderate hydrogen level, favorable stress (+125 MPa), and good uniformity—making it the most practical candidate for integration into both filterbank and PPC structures.

Future work should focus on direct measurement of dielectric loss tangent and TLS density under cryogenic conditions to validate the predicted performance in superconducting spectrometers.

Superconducting kinetic inductance detectors will play an important role in the future of exoplanet spectroscopy. Their low bandgap and the possibillity that they can be multiplexed into large arrays open up new opportunities where conventional semiconductors stop. A key requirement for the performance of these new detectors is the consistency of their quality factor (Q-factor). Variations in Q-factors, known as Q-scatter, result in nonuniform sensitivity and hold back scaling to larger systems.

In this thesis, detectors that differ in fabrication, pixel count and pixel spacing are analyzed and compared to find out what is the cause of Q-scatter. Possible causes include design errors, inaccurate fabrication, electromagnetic crosstalk, magnetic vortices and unbalanced transmission lines. Analysis showed Q-scatter is unlikely to be impacted by design, fabrication method, electromagnetic coupling or vortex forming. Also, no spatial relations, that indicated any transmission line effects, were observed. What is interesting however, is that the Q-factors of one of the chips seem to scatter all over again when measuring the chip again after trimming one of its components.

With the data available in this experiment it was not possible to give an concrete cause of Q-scatter. Furhter experiments, especially concerning the new scattering need to be conducted. Also, simulations using Sonnet v19 can give more insights in the origin of Q-scatter.

This Bachelor of Science thesis presents the development of a portable readout system for a graphenebased gas sensor array, aiming to bring advanced gas sensing technology from a controlled laboratory environment to practical field applications, such as greenhouses and vineyards. The project focuses on integrating various hardware components into a single printed circuit board (PCB) equipped with a microcontroller, ensuring accurate resistance measurement of graphene strips, generating programmable waveforms for micro hotplate control, and facilitating data communication via USB and Modbus interfaces. The design includes high-resolution analog-to-digital converters (ADCs) for precise current and voltage measurements, a digital-to-analog converter (DAC) for waveform generation, and a robust power management system supporting multiple power inputs. The system supports dual operation modes: interfacing with a desktop for laboratory use and functioning autonomously as an integrated sensor unit. Key challenges addressed include ensuring measurement accuracy, reliable sensor array connectivity, and user-friendly interfacing for both lab and field scenarios. Comprehensive test plans are outlined to verify the system’s performance, focusing on critical requirements such as resistance measurement accuracy, waveform generation, and communication interfaces. The successful implementation of a large part of this readout system demonstrates its potential for enhancing gas detection and monitoring in agricultural applications, providing a scalable solution for future deployment and development.

Extremely large telescopes (ELTs) are expected to be one of the most promising astronomical observation instruments when it comes to observing exoplanets. During observations, however, Earth’s atmosphere introduces optical distortion, which needs to be corrected. For this reason, a wavefront sensor (WFS) will be developed that comprises a 100 ⇥ 100 array of kinetic inductance detectors (KID), superconductor-based photodetectors. The main advantage of KIDs in an array is their ability to be multiplexed on a single read out line by designing each KID to operate at a different frequency. The signal of an individual KID can essentially be described as a dip in the transmission signal of the readout signal. Upon the fabrication of these KID arrays, however, these dips may have shifted as so-called frequency scatter (or f-scatter), which severely disorders the readout signal. The f-scatter cannot be determined based solely on the readout signal as it contains no information about which KID each individual signal originates from.
This paper manages to provide a solution in the form of an experimental method in which the KID array is scanned along the x- and y-axis to produce a spatial map. To realize this, an optical setup was designed and constructed, based on a single-lens system with a magnification of M = 1.22. By implementing a CCD camera, the KID array could be live imaged to align the setup accordingly. Thanks to numerous other alignment measures, the setup was able to scan the entire KID array along the x- and y-axis in 45 scans per axis. Based on the difference in transmission, a 45x45 spatial map was constructed, which was manually scaled down to 20x20. This 20x20 spatial map presented the location of KIDs on the fabricated detector array based on their measured operating frequency. By comparing this with the spatial map of the KID array design, the standard deviation in the fractional frequency deviation was determined, σ_δf/f = 5.92 · 10^-3. This result shows the experimental method is able to effectively unveil the severity of the f-scatter in the studied 20x20 KID array.
Despite the potency of the presented method, the biggest giveaway of its flaws is a reduced pixel yield on the 20x20 spatial map from 400 to 374 pixels. The developed data analysis is able recognize multiple complications, which can be mitigated by optimizing readout parameters to improve the quality of the signal. Additionally, one-to-one imaging is far too restricting for advanced scanning techniques due to its fixed M. Appropriate suggestions for improving the lens systems would be implementing the Cooke triplet or a two-lens system that utilizes the principle of virtual imaging.

DESHIMA (the Deep Spectroscopic High-Redshift Mapper) is a 347 channel superconducting spectrometer with spectral resolution R =500 that operates in the range of 220GHz to 440GHz and can therefore accurately measure the frequency of spectral lines in order to calculate redshift z.
This report investigates the sensitivity of DESHIMA-like spectrometers by investigating photon noise due to Poisson and bunching effects. It gives a broad overview of photon statistics and explains, through an analogous model, that photon bunching occurs due to an underlying change in the probabilistics, rather than the act of detecting itself. After that I investigate photon and quasiparticle recombination noise for a DESHIMA-like spectrometer with Lorentzian filters and find a closed form equation for NEP per channel for a constant power spectral density arriving at the filters.
Previously the bandwidth of the filters was assumed to be negligible, resulting in an overestimation of the bunching. Because the photons that are impinging on the detector span a bigger bandwidth, the bunching is a factor of π/2 smaller than previously approximated.
This NEPτ is defined at an integration time of τ=0.5s. For other integration times this is scalable, however this will only hold while the integration time is much bigger than the coherence time τ≫tcoh. Because of the correlation between photons arriving shorter than a coherence time apart, the scaling of the NEPτ drops in cases when τ≫̸tcoh.

Finally I propose and describe modifications to the sensitivity model DESHIMA uses. The following features have been be improved and added:

- Integrate over the entire power spectrum when calculating photon noise
- Use arbritatry filter designs loaded from a file
- Improve estimations of the quantities that express sensitivity

I compare the proposed modifications to the old model, which has previously been compared with measurement results, and use it to validate the changes. Other than the previously mentioned factor of π/2 for the bunching term and the smoothing out in local extrema, the modified simulation results are similar to the old model. This is because the Lorentzian filters have a small bandwidth ν≫Δν, such that the previous narrowband approximation held for most non-extreme cases.

A gas-cell-based calibration setup was designed to evaluate the wideband response of sub-millimeter spectrometers like DESHIMA (DEep Spectroscopic High-redshift MApper). The use of low pressure gas emission spectra allowed for accurate calibration of the absolute frequency response, and to test the detectability of faint emission spectra with long integration times. This is important to understand and evaluate systematic errors and noise profiles of sub-millimeter astronomical spectrometers before their telescope campaigns.

The setup consisted of a low pressure (~mbar) gas at room temperature in a high vacuum (<10^-3 mbar) chamber in front of a 77K N₂ background. A double-winged rotating chopper was used for signal modulation of the on- and off-source paths to reduce the low-frequency noise profile. The setup has been able to successfully detect the emission spectra of nitrous oxide at 30 mbar and methanol at 1 mbar in the frequency range of 332 to 377 GHz with the prototype DESHIMA spectrometer. Our models showed that lower pressures should be detectable over similar averaging times. The standing spectrum showed to be too irregular for detecting spectral lines in a single measurement. A second measurement was required to subtract the standing features, which extended the total time required beyond the current system stability.

Detailed analysis into optical resonances has shown the importance of anti-reflective (AR) coatings on the main optical interfaces to improve the detectability of the emission spectra. We adapted sub-wavelength pyramid gratings milled into TOPAS windows to reduce a standing wave in the output spectrum of the gas cell setup. Stability of the setup was shown for observation times of up to ~10³ seconds before environmental
noises became dominant. Extensive stability testing has shown the impact of key components in the setup. A two-stage post-processing algorithm was developed to successfully reduce instabilities in the data by removing linear drifts and by removing the common profile over simultaneous read-out data.

With the strict Paris climate goals, all eyes are set on the development of sustainable solutions that can replace or improve commercial solutions. This thesis revolves around the design and implementation of a subsystem for the creation of a solar powered drone. The goal of the solar powered drone is increasing the flight range of a commercial drone with the addition of photovoltaic (PV) panels. The subsystem designed and implemented in this thesis is split up into two separate systems namely, the control part and the image processing part. The control part revolves around the design, implementation and validation of Maximum Power Point Tracking (MPPT) for the PV panels. The image processing part revolves around the design, implementation and validation of an albedo processing pipeline.
For the MPPT, a variable step size perturb and observe algorithm has been implemented with a worse case tracking delay of 40 milliseconds during a change of irradiation from $900 W/m^2$ to $100 W/m^2$ and and more than 99\% power efficiency in steady state conditions. For the albedo pipeline, multiple RAW images are loaded one after another. Vignette correction is applied making the pixel values at the edges and the center of the image compatible with each other. The user can annotate a known reference target that is used to calibrate the albedo generation. Finally, the images are stitched together using Open Drone Map to create a complete albedo map. The results indicate accurate visible band albedo generation, however additional sensors would be needed to obtain wide band albedo generation.

Sustainable energy technologies are ever-increasing in popularity, not only among companies but also among consumers. Photovoltaic, or PV, cells are amongst the most well known in this field. This project was set up for designing a PV-powered UAV that is able to generate an albedo map of an area equal or bigger than the campus of the TU Delft in a single run. PV cells, however, are highly susceptible to changes in weather conditions and have a range of voltages at which these cells can supply power. Besides that, unnecessary losses occur if the so-called ’Maximum Power Point’ (MPP) is not tracked. In this thesis, a boost converter is proposed for the aforementioned system to implement the maximum power point tracking and supply the, by the PV system produced, power as efficiently as possible to the UAV power system.