Nanoplasmonics as enabler of room-temperature quantum nanophotonic networks (Invited), Ortwin Hess Coffee break (11:00 -11:20) Track 1 -Room 2.1 Track 2 -Room 2.2 Track 3 -Room 2.3 Track 4 -Room 3.1 Track 5 -Room 3.2 Track 6

“ M id- I nfra R ed ( MIR ) fiber photonics” is an important emerging technology worldwide. The MIR spectral region (3 μm wavelength) offers great potential for molecular sensing systems that will translate across sectors from security to healthcare; MIR laser cutting and welding at new wavelengths of soft materials will include medical surgery of human tissue. Chalcogenide glasses present windows within the 1–20 μm region and chalcogenide glass optical fibers are suitable for routing MIR light and as active laser sources. Chapter 8 is a critical review of the last 10 years’ research on lanthanide-ion doped chalcogenide bulk glasses and fibers up to, and including, the advent of bulk glass lasing, at >5 μm, in 2020 and 2021. Photoluminescent behavior is critically analyzed, including absorption and emission cross-sections, lifetimes, branching ratios of praseodymium, dysprosium, terbium and samarium ions doped into a variety of chalcogenide glass hosts. Potential electro-optic traps in chalcogenide glass hosts, as well as optical traps, are discussed for the first time.

In this contribution experimental investigation of acousto-optically Q-switched erbium-doped fluorozirconate fiber laser is presented. Under the repetition rate of 1 kHz laser produces pulses with the shortest duration of 20 ns and the maximum pulse energy of 180 μJ, corresponding to a maximum peak power of 9 kW.

This Letter, to the best of our knowledge, reports mid-infrared fiber lasing beyond 5 µm at room temperature for the first time, Ce3+-doped, chalcogenide glass, step index fiber employed in-band pumping with a 4.15 µm quantum cascade laser. The lasing fiber is was 64 mm long, with a calculated numerical aperture of 0.48 at the lasing wavelengths. The core glass was Ge15As21Ga1Se63 atomic % (at. %), doped with 500 parts-per-million-by-weight Ce, with a 9 µm core diameter. The cladding glass was Ge21Sb10Se69 at. % with a 190 µm outer diameter. As pump power increases continuous wave lasing corresponding to the 2F7/2→2F5/2, transition in the Ce3+ ion occurs at 5.14 µm, 5.17 µm, and 5.28 µm.

In this contribution a discussion of design and practical realization of dysprosium ion doped, and erbium ion doped, fluoride glass fiber lasers is given. The specific operating wavelength range that is covered corresponds is near 3000 nm. The discussion is centered around the pulsed Q-switched operation of the fiber laser.

We present results from the development of a fiber-coupled Acousto-Optic modulator (Fiber-Q (R)) operating at near-UV and blue wavelengths. A conventional TeO2 based Bragg diffraction design is introduced for short wavelengths optical input. Pure silica core single mode fibers (both Polarisation Maintaining (PM) and non-PM) are used as coupling fibers for their transmission at these wavelengths, and to avoid the possibility of photo darkening. The end of the fibers are fused with silica end-caps, lowering the power density on their fiber-air interfaces to achieve a higher power handling. The Fiber-Q (R) can be optimized for multiple wavelengths (including 397nm or 422nm) and can accept power levels of up to 100mW. A hermetically sealed package is selected to provide a clean in-package environment thus protecting the optics from damage caused by external contamination. In this presentation we report details of the design, and test results of a fiber-coupled Acousto-Optic modulator that demonstrates the performance required for use in ion-trap quantum information processing applications.

The extension of supercontinuum (SC) sources into the mid-infrared, via the use of uoride and chalcogenide optical fibers, potentially offers the high radiance of a laser combined with spectral coverage far exceeding that of typical tunable lasers and comparable to traditional black-body emitters. Together with advances in mid-IR imaging detectors and novel tunable filter designs, such supercontinua hold considerable potential as sources of illumination for spectrally-resolved microscopy targeting applications such as rapid histological screening. The ability to rapidly and arbitrarily select particular wavelengths of interest from a broad emission spectrum, covering a wide range of biologically relevant targets, lends itself to image acquisition only at key relevant wavelengths leading to more manageable datasets. However, in addition to offering new imaging modalities, SC sources also present a range of challenges to successful integration with typical spectral microscopy instrumentation, including appropriate utilisation of their high spatial coherence. In this paper the application of SC sources to spectrally-resolved microscopy in the mid-IR is discussed and systems-integration considerations specific to these sources highlighted. Preliminary results in the 3-5μm region, obtained within the European FP7 project MINERVA, are also presented here.

In recent years most research on fibre lasers has been focused on the 1, 1.5, and 2 μm wavelength ranges using rare-earth ions such as Yb, Er, Tm, or Ho in silicate glass hosts. This approach led to remarkably high power and high energy systems. Regarding direct laser sources emitting around 3 μm with comparable performance only few reports can be found in literature. High peak power lasers emitting here have significant potential for applications in medicine because of the strong absorption peak of water containing substances, e.g. biological tissue [1]. Although ZBLAN glass fibres have poor thermal properties there are several benefits for using ZBLAN based mid-IR lasers, e.g. low phonon energy and high transmission up to 3.5 μm.

Acousto Optic Tunable Filters (AOTFs) are solid-state, electronically addressable random-access optical pass-band filters, they are also inherently polarisation-selective. Devices with apertures larger than 10mm×10mm suitable for imaging applications are now routinely manufactured. The access time of less than 20μs gives rise to operational speeds significantly faster than is achievable with alternative technologies. These factors can be exploited to realise a polarimetric spectral-imaging system capable of flexible operation at high-speed. Additionally the band-sequential operation with the ability of random access can further increase the operational speed since it is not necessary to sweep continuously across the spectrum and so acquire unwanted data. The addition of further polarising components such as retardation plates further enhance the performance as a polarimeter, with the potential of acquiring the full Stokes parameters. By exploiting the undiffracted 0-order output an RGB image of the scene as viewed through a common objective may be captured, delivering a detailed real-time image to the operator. Any areas of interest identified by the HSI may be highlighted in false-colour on the display.