{"product_id":"shelyak-op0024","title":"Shelyak Instruments 200µm Calibration Optical Fiber - 20m","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e20 meter length for flexible observatory layouts\u003c\/li\u003e\n\u003cli\u003e200µm core diameter optimized for calibration sources\u003c\/li\u003e\n\u003cli\u003eSecure FC-FC connectors for standard astronomical instruments\u003c\/li\u003e\n\u003cli\u003eNumerical Aperture of 0.22\u003c\/li\u003e\n\u003cli\u003eDurable stainless steel protective sheathing\u003c\/li\u003e\n\u003cli\u003eSignal attenuation less than 0.5dB\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\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 Instruments 200µm Calibration Optical Fiber - 20m\u003c\/h2\u003e\n\u003cp\u003eThis Shelyak Instruments 20-meter optical fiber uses a 200µm core to deliver a stable, high-fidelity signal for calibrating fiber-fed Echelle spectrographs like the eShel or Whoppshel. The cable features industry-standard FC-FC connectors and a numerical aperture of 0.22, protected by a durable stainless steel sheath. With signal transmission close to 100% and total attenuation under 0.5dB, it ensures your calibration source light reaches the spectrograph with minimal loss, regardless of the 20-meter distance.\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\u003e200µm Core for High-Fidelity Spectrograph Calibration\u003c\/h3\u003e\n\u003cp\u003eThe 200µm core diameter is specifically sized to transmit light from a calibration unit to the spectrograph's fiber injection and guiding unit (FIGU). This diameter ensures a clean, uniform illumination of the spectrograph slit, which is essential for obtaining accurate and repeatable wavelength and flat-field calibrations. It is optimized for the controlled environment of a calibration lamp, not for collecting faint starlight.\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\u003eRobust 20-Meter Construction with FC-FC Connectors\u003c\/h3\u003e\n\u003cp\u003eA generous 20-meter length provides the flexibility to position your spectrograph and calibration unit anywhere in the observatory or lab without signal degradation. The fiber is protected by a stainless steel sheath, safeguarding it from crushing or kinking during setup and use. Standard FC-FC connectors provide a secure, repeatable physical connection to Shelyak instruments and other compatible hardware.\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\u003eNear-100% Transmission for eShel and Whoppshel Systems\u003c\/h3\u003e\n\u003cp\u003eThis fiber is engineered for minimal signal loss, with a transmission rate approaching 100% through the fiber itself. Total system attenuation is kept below 0.5dB, a figure that remains constant even at this 20-meter length. While the fiber is highly efficient, remember that the primary source of light loss occurs at the connectors; ensuring clean, secure junctions is key to maintaining a pure calibration signal for your eShel or Whoppshel system.\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\"\u003eWhy is the core diameter 200µm for this Shelyak calibration fiber?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e200µm core diameter\u003c\/strong\u003e is specifically chosen to match the requirements of calibration units used with spectrographs like the Shelyak eShel. It provides a broad, even illumination of the spectrograph slit, which is critical for accurate flat-fielding and wavelength calibration.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the 20-meter length of this fiber reduce my calibration signal strength?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. The fiber itself has a transmission rate close to 100%, and the total attenuation is rated at \u003cstrong\u003eless than 0.5dB\u003c\/strong\u003e. This low level of loss is independent of the fiber's length up to 20 meters, so you will not see a noticeable drop in signal compared to a shorter fiber.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat systems is the Shelyak 200µm fiber compatible with?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis fiber is primarily designed for Shelyak Instruments' own fiber-fed spectrographs, such as the \u003cstrong\u003eeShel\u003c\/strong\u003e and \u003cstrong\u003eWhoppshel\u003c\/strong\u003e systems. It uses standard \u003cstrong\u003eFC-FC connectors\u003c\/strong\u003e, making it potentially compatible with other astronomical or laboratory equipment that uses the same interface.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eI am setting up an eShel spectrograph in my observatory. Is this 20-meter fiber the correct one for connecting the calibration unit to the FIGU?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, this is the correct fiber for that purpose. The \u003cstrong\u003e200µm core\u003c\/strong\u003e is designed to carry the light from the calibration module to the Fiber Injection \u0026amp; Guiding Unit (FIGU) of the eShel. The 20-meter length offers ample flexibility for routing the cable between your telescope and the spectrograph.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat are FC-FC connectors and why are they used on this calibration fiber?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eFC (Ferrule Connector) connectors are a type of fiber optic connector known for their secure, screw-on coupling mechanism. They provide excellent mechanical stability and repeatable alignment, which is critical in spectroscopy to prevent signal fluctuations. The \u003cstrong\u003eFC-FC\u003c\/strong\u003e designation means the cable has this type of connector on both ends.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eMy calibration lamp seems dim when using the 20-meter fiber with my Whoppshel system. Is the fiber causing the light loss?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt is unlikely the fiber itself is the cause, as its attenuation is less than 0.5dB. The most common source of signal loss in a fiber optic system is at the connection points. Ensure both \u003cstrong\u003eFC-FC connectors\u003c\/strong\u003e are perfectly clean (free of dust) and securely tightened to minimize junction loss and maximize signal throughput.\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\u003e200µm\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-FC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNumerical Aperture (NA)\u003c\/td\u003e\n\u003ctd\u003e0.22\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProtective Sheath\u003c\/td\u003e\n\u003ctd\u003eStainless Steel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSignal Attenuation\u003c\/td\u003e\n\u003ctd\u003e\u0026lt;0.5dB (independent of length up to 20m)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFiber Transmission\u003c\/td\u003e\n\u003ctd\u003eClose to 100%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Loss Source\u003c\/td\u003e\n\u003ctd\u003eJunctions at connector level\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\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":52943034384669,"sku":"SHK-OP0024","price":731.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Shelyak-Calibration-optical-fiber-200-m-20m-1_30bcab48-6050-4176-97b9-b25001d0cf83.jpg?v=1789616021","url":"https:\/\/davidastro.com\/en-us\/products\/shelyak-op0024","provider":"David Astro","version":"1.0","type":"link"}