This research presents the integration of ultra low loss (<1dB/cm) silicon nitride waveguides with a superconducting single photon detector with photon number resolving (PNR) capability - the Microwave Kinetic Inductance Detector - introducing a new photonic integrated circuit platform. Our approach is to integrate waveguides and MKIDs on a sapphire substrate, which minimizes the two level system noise for the MKIDs and serves as a bottom cladding for waveguides. Silicon nitride is used as the core of the waveguides and either SiO2 or SiOxNy is used as the top cladding. We present findings on how the fabrications processes -- including the materials used and the method of deposition -- affect the quality of the MKIDs and waveguides. The integrated system would ultimately be used to make photon number resolving detectors for quantum information applications and high resolution spectrometers for astrophysics and metrology applications.
MagAO-X is a visible to near-IR AO system that will enable a suite of instruments to perform high-contrast, high-resolution science. During its "Phase II" plan a 10-kilopixel Microwave Kinetic Inductance Detector (MKID) IFU will be deployed as a science camera behind MagAO-X. MKIDs are photon-counting detectors with energy resolution up to 30. The photon counting capability and readout allow for microsecond time resolution with no associated read noise. As a consequence of the high readout rate the MKID camera can be used as a Focal Plane Wavefront Sensor (FPWFS) allowing real-time speckle control while simultaneously taking science observations. With the high resolution and contrasts delivered by MagAO-X the MKID camera will aim to directly image and characterize exoplanets in the near-IR. The camera's IR filters can also be replaced with visible filters that will allow for further characterization and the potential for exploration of the inner regions of circumstellar disks.
We present an on-sky demonstration of a post-processing technique for companion detection called Stochastic Speckle Discrimination (SSD) and its ability to improve the detection of faint companions using SCExAO and the MKID Exoplanet Camera (MEC). Using this SSD technique, MEC is able to resolve companions at a comparable signal to noise to other integral field spectrographs solely utilizing photon arrival time information and without the use of any PSF subtraction techniques. SSD takes advantage of photon counting detectors, like the MKID detector found in MEC, to directly probe the photon arrival time statistics that describe the speckle field and allows us to identify and distinguish problematic speckles from companions of comparable brightness in an image. This technique is especially effective at close angular separations where the speckle intensity is large and where traditional post-processing techniques, like ADI, suffer.
We develop a simple coordinate transformation that can be employed to compensate for the nonlinearity introduced by a microwave kinetic inductance detector’s (MKID) homodyne readout scheme. This coordinate system is compared to the canonically used polar coordinates and is shown to improve the performance of the filtering method often used to estimate a photon’s energy. For a detector where the coordinate nonlinearity is primarily responsible for limiting its resolving power, this technique leads to increased dynamic range, which we show by applying the transformation to data from a hafnium MKID designed to be sensitive to photons with wavelengths in the 800- to 1300-nm range. The new coordinates allow the detector to resolve photons with wavelengths down to 400 nm, raising the resolving power at that wavelength from 6.8 to 17.
The Planetary Imaging Concept Testbed Using a Recoverable Experiment-Coronagraph (PICTURE-C) experiment is a balloon-borne observatory for high-contrast imaging of debris disks and exoplanets around nearby stars. This experiment will use a 10,000-pixel Microwave Kinetic Inductance Detector (MKID) instrument as its science camera. The PICTURE-C MKID Camera is an integral field spectrograph (IFS) with a bandpass of λ = 540 − 660 nm that sits behind a modest adaptive optics system and coronagraph which promise to achieve contrast ratios down to 10-7 from 1.7 to 10 λ/D (0.35” to 2.1”). The MKIDs are photon counting detectors promising a resolution R up to 20 for the PICTURE-C mission. The ability to count photons with microsecond time resolution will allow the MKID camera to double as a Focal Plane Wavefront Sensor (FPWFS), helping to discriminate between speckles and circumstellar objects in real time and in post-processing. The intrinsic spectral resolution of the detectors will allow for further characterization of the debris disks and exoplanets around the stars targeted during its flight. The visible light observations taken with this instrument will complement infrared observations taken from the ground and serve to demonstrate MKIDs utility in a space-like environment. For this poster, we will introduce and discuss the PICTURE-C MKID Camera.
The size and cost of astronomical instruments for extremely large telescopes (ELTs), are pushing the limits of what is feasible, requiring optical components at the very edge of achievable size and performance. Operating at the diffraction-limit, the realm of photonic technologies, allows for highly compact instruments to be realized. In particular, Integrated Photonic Spectrographs (IPSs) have the potential to replace an instrument the size of a car with one that can be held in the palm of a hand. This miniaturization in turn offers dramatic improvements in mechanical and thermal stability. Owing to the single-mode fiber feed, the performance of the spectrograph is decoupled from the telescope and the instruments point spread function can be calibrated with a much higher precision. These effects combined mean that an IPS can provide superior performance with respect to a classical bulk optic spectrograph. In this paper we provide a summary of efforts made to qualify IPSs for astronomical applications to date. These include the early characterization of arrayed waveguide gratings for multi-object injection and modifications to facilitate a continuous spectrum, to the integration of these devices into prototypical instruments and most recently the demonstration of a highly optimized instrument directly fed from an 8-m telescope. We will then outline development paths necessary for astronomy, currently underway, which include broadening operating bands, bandwidth, increasing resolution, implementing cross-dispersion on-chip and integrating these devices with other photonic technologies and detectors such as superconducting Microwave Kinetic Inductance Detector arrays. Although the focus of this work is on IPS applicability to astronomy, they may be even more ideally suited to Earth and planetary science applications.
Mazin Lab at UCSB is developing MKID instrument for astronomy at near infrared, optical and ultraviolet wavelength. We use MIKDs as single photon detectors by measuring the arrival time of incoming photons with an accuracy of a few microseconds and with a relatively high energy resolution (R~10 at 1um). We fabricate kilopixels array of MKIDs and we incorporate them in our own instruments for UVOIR astronomy with the main application being exoplanets direct imaging.
We present the work being made in our lab in the development and fabrication of 10 to 20k pixels arrays for the DARKNESS (Dark-speckle Near-IR Energy-resolved Superconducting Spectrophotometer) and MEC (MKID Exoplanet Camera) instruments, respectively. The 6-step fabrication process has been upgraded over the last months in order to improve the sensitivity of the arrays. The detectors are made of platinum silicide (PtSi) since MKIDs with very high internal quality factor have been successfully fabricated from this material. Furthermore, PtSi with very uniform superconducting properties over 4inch substrate are much more easier to deposit than the regular TiN used in most existing MKIDs technology. Among various upgrades, we coated the PtSi sensitive area with a SiO2/Ta2O5 bi-layer in order to reduce the reflection of optical photons hitting the detectors. The light absorption is increased by a factor of 2 in the instruments bandwidth. The DARKNESS instrument has been successfully commissioned last summer and MEC, the world largest superconducting camera, is installed at the Subaru telescope since the beginning of the year. Our effort leads to the fabrication of arrays of detectors with a median internal quality factor of 100 000 with an energy resolution of 10 at 1um and a pixel yield approaching 95%.
In addition, we will present new MKID design in which the conventional meander inductor and interdigitated capacitor are replaced by a square inductor and a large parallel plate capacitor made of two metal plates separated by a ~10-nm thick dielectric layer. This parallel plate design allows us to drive the MKIDs at a higher power, which in turns should increase the sensitivity of the detectors. Following promising results from our first design, second generation of parallel plate MKID devices have been made from Hf/HfO2/Nb tri-layers deposited in-sit. We obtained high quality factor from the parallel plate MKIDs and we were able to detect photons with this new MKIDs design. Another way to improve the sensitivity of MKIDs is to use a low Tc material, compared to Tc ~ 1K usually used. We fabricated MKIDs arrays with superconducting Hafnium, Tc = 450mK, and we demonstrated that resonators with very high internal quality factors Qi~300 000 and an energy resolution of 9 at 808nm can be achieved.
Excess phase noise has been observed in microwave kinetic inductance detectors (MKIDs) which prevents the
noise-equivalent power (NEP) of current detectors from reaching theoretical limits. One characteristic of this
excess noise is its dependence on the power of the readout signal: the phase noise decreases as the readout
power increases. We investigated this power dependence in a variety of devices, varying the substrate (silicon
and sapphire), superconductor (aluminum and niobium) and resonator parameters (resonant frequency, quality
factor and resonator geometry). We find that the phase noise has a power law dependence on the readout power,
and that the exponent is -1/2 in all our devices. We suggest that this phase noise is caused by coupling between
the high-Q microwave resonator that forms the sensitive element of the MKID and two-level systems associated
with disorder in the dielectric material of the resonator. The physical situation is analogous to the resonance
fluorescence in quantum optics, and we are investigating the application of resonance fluorescence theory to
MKID phase noise.
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.