Frequently Asked Questions
1. What are thin film filters?
Thin film filters (TFFs) are a type of optical (or spectral) filter – filters that transmit and/or block (reflect) light with particular properties, such as particular range of wavelengths. Optical filters are used in many applications, such as in optical telecommunications networks, spectrography, and other optical instrumentation.
In order to exhibit thin-film optics, the thickness of the layers of material must be on the order of the wavelengths of visible light (about 500 nm).TFFs typically comprise alternating layers of high (H) and low (L) index materials deposited on a substrate, where the choice of materials, the number of layers and the thickness of each layer governs the filter performance for light of a given wavelength, angle of incidence and polarization.To obtain the desired filter performance, it is critical to have accurate optical constants of all the materials used in the filter the layer and to deposit all the layer thicknesses very accurately.
2. What are the advantages of thin film optical filters?
Thin film optical filters have a number of advantages compared to other technologies for manipulating the light spectrum. For example, TFFs:
- Can be fabricated in small sizes (i.e., 1.5x1.5x1.0mm)
- Are environmentally stable
- Are easy to manipulate in a device
- Possess a very low intrinsic temperature coefficient
- Are relatively inexpensive with prototype quantities deliverable in a short time period (two to six weeks depending on the filter complexity).
3. How should I specify custom requirements for a TFF when requesting a quote?
The filter specifications required will vary according to the desired filter type. We have simplified this process through our dynamic Custom Filters Request for Quote form, which will intelligently guide you through the specifications you need to provide for a particular filter type. You are invited to fill out as many of the specifications that you know.If the value of a particular filter specification is not known, simply leave it blank and our sales personnel will be happy to assist you in completing the filter specification form.
In general, typical filter specifications will include the wavelength and angle of incidence range of interest; the polarization state of light; the filter temperature coefficient; the desired filter dimensions (width x length x thickness); substrate material, entrance and exit media; filter quantities required.
For a specific filter product type, additional specifications are required. For example,
- GFF Filters : PPEF is specified along with the target curve data
- Solid Etalons : Free Spectral Range (FSR) and finesse (F) are specified.
- Single Cavity Etalons : -3 dB bandwidth (equivalent to the Full-Width,Half-Maximum (FWHM) is specified
- BandPass, Edge Pass, CWDM Filters : Passband and Reflect band regions; allowed insertion loss and ripple in passband, blocking levels are all required
4. How do I generate a Request for Quote (RFQ)?
On this website, you can either click a "Request a Quote" corresponding to the desired filter product or you can send your request to inquiries@iridian.ca. In either case, Iridian’s sales personnel will get back to you within 1 business-day with regards to your RFQ.
5. What information is needed for a Purchase Order (PO)?
If you decide to place a PO after receiving a quotation, please include the following information:
? Quotation number and date,
? Preferred courrier and your account number with that courrier,
? If you are a first time buyer and request a 30 days credit, please include credit references.
6. Can I order online?
This is not possible at the moment. Please contact us by phone or e-mail if you wish to use a credit card. We currently accept only Visa (certain conditions apply).
