{"product_id":"shelyak-pf0051","title":"Shelyak 50µm Object Fiber - 20m","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e50µm Core Diameter\u003c\/li\u003e\n\u003cli\u003e20 Meter Length\u003c\/li\u003e\n\u003cli\u003eLess than 0.5dB Attenuation\u003c\/li\u003e\n\u003cli\u003e380-800nm Spectral Range\u003c\/li\u003e\n\u003cli\u003eFC-Type Connectors (Both Ends)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eShelyak 50µm Object Fiber - 20m\u003c\/h2\u003e\n\u003cp\u003eThis 20-meter Shelyak object fiber uses a 50µm core to transmit starlight from your telescope's Fiber Injection and Guiding Unit (FIGU) directly to a compatible spectroscope like the eShel. Its High-OH fiber construction is optimized for the 380 to 800nm spectral range, while the 0.22 numerical aperture efficiently couples light into the system with less than 0.5dB of total attenuation.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eA 50µm Core for High-Resolution eShel Spectroscopy\u003c\/h3\u003e\n\u003cp\u003eEngineered as the primary light path for Shelyak's eShel system, this fiber's 50µm core diameter is precisely matched to the instrument's design for optimal resolution. The 20-meter length provides ample flexibility for permanent observatory setups where the telescope and spectroscope may be positioned far apart. Both ends are terminated with robust FC-type connectors for a secure, repeatable connection between the FIGU and the spectrograph.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eHigh-OH Fiber: \u0026lt;0.5dB Attenuation from 380-800nm\u003c\/h3\u003e\n\u003cp\u003eThis fiber uses \"High-OH\" glass, which enhances transmission in the blue and ultraviolet portions of the spectrum, making it effective from 380nm to 800nm and beyond. The total signal loss is rated at less than 0.5dB, a figure dominated by the connection points rather than the fiber itself. This means transmission is near 100% along the 20-meter length, ensuring that valuable photons from your target reach the sensor.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the purpose of the Shelyak 50µm object fiber in an eShel system?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis is the \"object\" fiber, designed to carry the starlight collected by the telescope to the spectroscope. It physically connects the Fiber Injection and Guiding Unit (FIGU) at the telescope to the main eShel instrument, which can be located up to 20 meters away.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy is the attenuation of the 20m fiber rated at \u0026lt;0.5dB, the same as shorter fibers?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eFor modern optical fibers of this length, signal loss along the glass itself is negligible (close to 100% transmission). The vast majority of the \u0026lt;0.5dB attenuation occurs at the two FC connector junctions. Because the number of connections is the same regardless of length, the total attenuation remains constant across 5m, 10m, and 20m versions.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use this 50µm object fiber to study the Balmer series in Vega (Alpha Lyrae) with an eShel?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. The fiber's High-OH glass provides excellent transmission from 380nm to 800nm. This range comfortably covers the entire visible Balmer series of hydrogen, from H-alpha (656nm) down to H-beta (486nm), H-gamma (434nm), and H-delta (410nm), making it ideal for stellar classification of A-type stars like Vega.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does \"High-OH\" mean for this 50µm fiber?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003e\u003cstrong\u003e\"High-OH\"\u003c\/strong\u003e refers to a high concentration of hydroxyl groups in the silica glass, which significantly improves the fiber's transparency to blue and ultraviolet (UV) light. This makes the fiber highly efficient for spectroscopy in the 380nm to 800nm range, ensuring faint signals in the blue end of the spectrum are not lost.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eI have my telescope and eShel spectroscope set up 15 meters apart. Is the 20m fiber the right choice?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the 20-meter length is the correct choice. It provides the necessary distance with extra slack to prevent strain on the fiber or connectors as the telescope moves. Since attenuation is independent of length in this range, there is no performance penalty for choosing the 20m version over a shorter one.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat kind of connectors does the Shelyak 50µm object fiber use?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe fiber is terminated with \u003cstrong\u003eFC-type connectors\u003c\/strong\u003e on both ends. This is a standard, robust connector used in spectroscopy and telecommunications to ensure precise and repeatable alignment of the fiber core.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eCore Diameter\u003c\/td\u003e\n\u003ctd\u003e50µm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLength\u003c\/td\u003e\n\u003ctd\u003e20 meters\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eConnectors\u003c\/td\u003e\n\u003ctd\u003eFC type (both ends)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNumerical Aperture\u003c\/td\u003e\n\u003ctd\u003e0.22\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAttenuation\u003c\/td\u003e\n\u003ctd\u003e\u0026lt;0.5dB (independent of length)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFiber Type\u003c\/td\u003e\n\u003ctd\u003eHigh-OH\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUsable Spectral Range\u003c\/td\u003e\n\u003ctd\u003e380nm - 800nm+\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFiber Transmission\u003c\/td\u003e\n\u003ctd\u003eApproximately 100% over this length\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003e50µm Object Fiber - 20m\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Shelyak_eShel_Manual.pdf\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eShelyak eShel Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/shelyak-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eShelyak 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Shelyak","offers":[{"title":"Default Title","offer_id":52943039758621,"sku":"SHK-PF0051","price":705.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Shelyak-50-m-object-fiber-5m-1_62cf15ba-34a3-4301-995e-ec23a3494a3b.jpg?v=1789616118","url":"https:\/\/davidastro.com\/products\/shelyak-pf0051","provider":"David Astro","version":"1.0","type":"link"}