Iridian Spectral Technologies would like to congratulate Spartan Bioscience on obtaining Health Canada approval this week for use of the Spartan Cube for COVID-19 testing. We are proud that Iridian’s optical filters are a key component in this instrument.
As data storage and computing resources enter the cloud, the demand for storage and data transfer capacity in the Data Center has increased dramatically.
In wavelength-division multiplexer (WDM) and passive optical network (PON) modular design, single band pass filters and multiple band pass filters are used for the same purpose: permitting narrow wavelength ranges to pass through while rejecting wavelengths outside that range (known as the filter’s upper and lower cutoff frequencies).
Multiple band pass filters are used to transmit two or more standard coarse wavelength division multiplexing (CWDM) channels, separating them from the other CWDM bands — replacing two or more single band pass filters with a single component.
Much like vehicle hand cranks in their day, the use of a gain flattening filter (GFF) paired with a wavelength- division multiplexer (WDM) in optical fiber amplifiers – such as erbium-doped fiber amplifiers (EDFA) — has been accepted not because it is ideal, but because a superior solution had yet to be created. Until now.
This article explains what a Hybrid GFF is and how it works. It also details the advantages of using Iridian Spectral Technologies’ Hybrid GFFs in lieu of a conventional two-filter setup in EDFA and other optical filter applications.
The wavefront error (WE) of a surface with an optical coating (“filter”) is ideally measured at the in-band wavelength of the filter. However, quite often this is not possible, requiring that the filter be measured at an out-of-band wavelength (typically 633 nm), assuming that the filter transmits (for transmitted WE, or TWE) or reflects (for reflected WE, or RWE) at this wavelength. This out-of-band TWE/RWE is generally assumed to provide a good estimation of the desired in-band TWE/RWE. It will be shown in this paper that this is not the case for a large class of filters (i.e., bandpass) where the group delay is significantly different at the in-band and out-of-band wavelengths and where the optical filter exhibits a thickness non-uniformity across the surface.
Raman spectroscopy probes the molecular vibrational and rotational modes of a material in order to detect and identify the material. Typically, laser light is incident upon the material and the scattered light is measured.
The excitation source (laser line) intensity is often to orders of magnitude greater than the Raman scattered signal. Therefore, edge pass (or notch) filters are required to block the Rayleigh scattered laser light while transmitting the red-wavelength shifted (Stokes) and/or the blue-wavelength shifted (Anti-Stokes) Raman scattered signal.
We live in the “Communications Age” – rapid access to information and connectivity to each other, anytime, nearly everywhere. But despite the massive strides that have been made in the past half century – from hardline telephony to the current ubiquitous wireless “smart” device connectivity – there is still further evolution to come that will necessitate extending the communications reach even further. While we have laid down a large physical infrastructure of wireline fiber-optic networks and wireless cellular base stations, the next advances in communications, 5G and machine-to-machine communications, will require “help from above” to blanket literally every corner of our planet with high speed, ultra-low latency, secure networks – telecom meet satcom.
