MEMS-enabled silicon photonic integrated devices and circuits

Photonic integrated circuits have seen a dramatic increase in complexity over the past decades. This development has been spurred by recent applications in datacenter communications and enabled by the availability of standardized mature technology platforms. Mechanical movement of wave-guiding structures at the micro- and nanoscale provides unique opportunities to further enhance functionality and to reduce power consumption in photonic integrated circuits. We here demonstrate integration of MEMS-enabled components in a simplified silicon photonics process based on IMEC's Standard iSiPP50G Silicon Photonics Platform and a custom release process

MEMS for Photonic Integrated Circuits

The field of microelectromechanical Systems (MEMS) for photonic integrated circuits (PICs) is reviewed. This field leverages mechanics at the nanometer to micrometer scale to improve existing components and introduce novel functionalities in PICs. This review covers the MEMS actuation principles and the mechanical tuning mechanisms for integrated photonics. The state of the art of MEMS tunable components in PICs is quantitatively reviewed and critically assessed with respect to suitability for large-scale integration in existing PIC technology platforms. MEMS provide a powerful approach to overcome current limitations in PIC technologies and to enable a new design dimension with a wide range of applications

Low-voltage silicon photonic MEMS switch with vertical actuation

We present a vertically movable silicon photonic MEMS switch realized in IMEC's standard silicon photonics platform followed by a dedicated postprocessing for MEMS release. The device has six optical ports, which enable four switching configurations with a safe electrical isolation of the switch's actuator. A low actuation voltage of 3.75 V is required to efficiently switch the optical signal from the drop port to the through port of the device. The device exhibits port extinctions of 16 dB and 26 dB at its OFF and ON states, respectively. With an insertion loss of 35 nm, this component paves the way for low-power scalable circuits in MEMS-enabled silicon photonics

Silicon photonic MEMS add-drop filter

We demonstrate a compact add-drop filter based on a MEMS ring resonator implemented in IMEC's iSiPP50G silicon photonics platform. The device exhibits a port extinction of 20 dB and a port isolation of > 50 dB, upon actuation range of 0 V to 27 V

Wafer-level vacuum sealing for packaging of silicon photonic MEMS

Silicon (Si) photonic micro-electro-mechanical systems (MEMS), with its low-power phase shifters and tunable couplers, is emerging as a promising technology for large-scale reconfigurable photonics with potential applications for example in photonic accelerators for artificial intelligence (AI) workloads. For silicon photonic MEMS devices, hermetic/vacuum packaging is crucial to the performance and longevity, and to protect the photonic devices from contamination. Here, we demonstrate a wafer-level vacuum packaging approach to hermetically seal Si photonic MEMS wafers produced in the iSiPP50G Si photonics foundry platform of IMEC. The packaging approach consists of transfer bonding and sealing the silicon photonic MEMS devices with 30 μm-thick Si caps, which were prefabricated on a 100 mm-diameter silicon-on-insulator (SOI) wafer. The packaging process achieved successful wafer-scale vacuum sealing of various photonic devices. The functionality of photonic MEMS after the hermetic/vacuum packaging was confirmed. Thus, the demonstrated thin Si cap packaging shows the possibility of a novel vacuum sealing method for MEMS integrated in standard Si photonics platforms

MORPHIC : programmable photonic circuits enabled by silicon photonic MEMS

In the European project MORPHIC we develop a platform for programmable silicon photonic circuits enabled by waveguide-integrated micro-electro-mechanical systems (MEMS). MEMS can add compact, and low-power phase shifters and couplers to an established silicon photonics platform with high-speed modulators and detectors. This MEMS technology is used for a new class of programmable photonic circuits, that can be reconfigured using electronics and software, consisting of large interconnected meshes of phase shifters and couplers. MORPHIC is also developing the packaging and driver electronics interfacing schemes for such large circuits, creating a supply chain for rapid prototyping new photonic chip concepts. These will be demonstrated in different applications, such as switching, beamforming and microwave photonics

Insomnia symptoms and repressive coping in a sample of older Black and White women

BACKGROUND: This study examined whether ethnic differences in insomnia symptoms are mediated by differences in repressive coping styles. METHODS: A total of 1274 women (average age = 59.36 ± 6.53 years) participated in the study; 28% were White and 72% were Black. Older women in Brooklyn, NY were recruited using a stratified, cluster-sampling technique. Trained staff conducted face-to-face interviews lasting 1.5 hours acquiring sociodemographic data, health characteristics, and risk factors. A sleep questionnaire was administered and individual repressive coping styles were assessed. Fisher's exact test and Spearman and Pearson analyses were used to analyze the data. RESULTS: The rate of insomnia symptoms was greater among White women [74% vs. 46%; χ(2 )= 87.67, p < 0.0001]. Black women scored higher on the repressive coping scale than did White women [Black = 37.52 ± 6.99, White = 29.78 ± 7.38, F(1,1272 )= 304.75, p < 0.0001]. We observed stronger correlations between repressive coping and insomnia symptoms for Black [r(s )= -0.43, p < 0.0001] than for White women [r(s )= -0.18, p < 0.0001]. Controlling for variation in repressive coping, the magnitude of the correlation between ethnicity and insomnia symptoms was substantially reduced. Multivariate adjustment for differences in sociodemographics, health risk factors, physical health, and health beliefs and attitudes had little effect on the relationships. CONCLUSION: Relationships between ethnicity and insomnia symptoms are jointly dependent on the degree of repressive coping, suggesting that Black women may be reporting fewer insomnia symptoms because of a greater ability to route negative emotions from consciousness. It may be that Blacks cope with sleep problems within a positive self-regulatory framework, which allows them to deal more effectively with sleep-interfering psychological processes to stressful life events and to curtail dysfunctional sleep-interpreting processes

Silicon photonic MEMS: exploiting mechanics at the nanoscale to enhance photonic integrated circuits

With the maturing and the increasing complexity of Silicon Photonics technology, novel avenues are pursued to reduce power consumption and to provide enhanced functionality: exploiting mechanical movement in advanced Silicon Photonic Integrated Circuits provides a promising path to access a strong modulation of the effective index and to low power consumption by employing mechanically stable and thus non-volatile states. In this paper, we will discuss recent achievements in the development of MEMS enabled systems in Silicon Photonics and outline the roadmap towards reconfigurable general Photonic Integrated Circuits

Integrin/Fak/Src-mediated regulation of cell survival and anoikis in human intestinal epithelial crypt cells: selective engagement and roles of PI3-K isoform complexes

In human intestinal epithelial crypt (HIEC) cells, the PI3-K/Akt-1 pathway is crucial for the promotion of cell survival and suppression of anoikis. Class I PI3-K consists of a complex formed by a catalytic (C) and regulatory (R) subunit. Three R (p85α, β, and p55γ) and four C (p110α, β, γ and δ) isoforms are known. Herein, we analyzed the expression of PI3-K isoforms in HIEC cells and determined their roles in cell survival, as well as in the β1 integrin/Fak/Src-mediated suppression of anoikis. We report that: (1) the predominant PI3-K complexes expressed by HIEC cells are p110α/p85β and p110α/p55γ; (2) the inhibition and/or siRNA-mediated expression silencing of p110α, but not that of p110β, γ or δ, results in Akt-1 down-activation and consequent apoptosis; (3) the expression silencing of p85β or p55γ, but not that of p85α, likewise induces Akt-1 down-activation and apoptosis; however, the impact of a loss of p55γ on both Akt-1 activation and cell survival is significantly greater than that from the loss of p85β; and (4) both the p110α/p85β and p110α/p55γ complexes are engaged by β1 integrin/Fak/Src signaling; however, the engagement of p110α/p85β is primarily Src-dependent, whereas that of p110α/p55γ is primarily Fak-dependent (but Src-independent). Hence, HIEC cells selectively express PI3-K isoform complexes, translating into distinct roles in Akt-1 activation and cell survival, as well as in a selective engagement by Fak and/or Src within the context of β1 integrin/Fak/Src-mediated suppression of anoikis