Application Notes, Learning Center
LiDAR, short for light detection and ranging, uses pulsed lasers to accurately calculate distances as well as correctly detect the size and shape of objects. The high resolution of the information — LiDAR can resolve to a few centimeters from more than 100 meters away — and the ability to create accurate model three-dimensional images have made the technology critical in many applications. Some uses include autonomous vehicles and automobile crash avoidance, surveying, environment, construction, agriculture, oil and gas exploration, and pollution modeling.
Application Notes, Learning Center
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.
Learning Center, Technical Notes
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.
Application Notes, Learning Center
qPCR instrument users need high sensitivity and pristine signal clarity to achieve numerous delicate tasks. The right combination of optical filters significantly improves this functionality.
Application Notes, Learning Center
Channel skip filters are components added to wavelength division multiplexing (WDM) add/drop modules — in both coarse wavelength division multiplexing (CWDM) and dense wavelength division multiplexing (DWDM) applications — to facilitate band splitting and to manage multiple ITU channels.
These filters feature narrow transitions from pass band to blocking band, minimizing lost channels while maintaining high spectral efficiency (i.e., limiting insertion loss) since the express channels undergo only one reflection.
Application Notes, Learning Center
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.
Application Notes, Learning Center
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.
Learning Center, Technical Notes
Abstract: Considerations when specifying transition pass bands, blocking bands, and transition widths include filter manufacturing tolerances, thermal tolerances and source/detector variations among others. These factors must be taken into account properly and...
How To, Learning Center
How to Clean Optical Filters?While the Iridian filters are hard coated filters, the filters are delicate and should be handled with care to avoid or minimize direct contact with any other optics. All Iridian filters may be cleaned using the following recommended method.
How To, Learning Center
Optical filters are used in many applications and the surface figure and wavefront distortion requirements of filters are dependent on where and how they are used. Whereas band-pass or clean-up functionality may only require control of the transmitted wavefront, dichroic beam-steering/splitting filters or wavelength selective mirrors likely require specification of both the transmitted and reflected beams. If filters are only used in sensing applications with very tolerant detector geometries, there may be no need, in practice, to put any constraints on the surface figure or wavefront distortion. It is important to understand where, when, how, and how much to specify wavefront distortion to ensure that functional requirements are guaranteed while unnecessary and costly constraints are avoided.
FAQ, Learning Center
What are optical thin film filters? How are optical thin film filters manufactured? Click here for frequently asked questions and answers.
Learning Center, Technical Notes
Gain Flattening Filter (GFFs), also known as gain equalizing filters, are used to flatten or smooth out unequal signal intensities over…
