LP675 Longpass Filter (T>85%@685-1750nm, OD5@200-665nm)

LP675 Longpass Filter (T>85%@685-1750nm, OD5@200-665nm)

Cut-on=675nm / T>85%@685-1750nm // OD5@200-665nm / dia12.5mm(unmounted)
$50.00
$50.00
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LP675 Longpass Filter (T>85%@685-1750nm, OD5@200-665nm)
  • LP675 Longpass Filter (T>85%@685-1750nm, OD5@200-665nm)
LP675 Longpass Filter (T>85%@685-1750nm, OD5@200-665nm)

LP675 Longpass Filter (T>85%@685-1750nm, OD5@200-665nm)

SO3040041
Cut-on Wavelength
Cut-on Wavelength
Cut-on=675nm
Transmission // Blocking
Transmission // Blocking
T>85%@685-1750nm // OD5@200-665nm
SO3040041n-d12.5u
In stock
$50.00
$50.00
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Stock Availability

Yes. Listed filters are generally available from stock, but final availability may depend on size and quantity.

  • Most filters are kept as medium-sized coated pieces
  • Final size is usually diced before shipment
  • Preparation time may vary for urgent orders, custom sizes, or larger quantities
Custom Size & Mounting

We can usually cut optical filters to custom outer sizes, depending on available coated material.

Custom size
  • Typical custom size range: 3 × 3mm to 60 × 60mm
  • Custom sizing changes the outer dimension only
  • Thickness normally follows the original filter specification
  • Final feasibility depends on coated material size and cutting requirements
Mounting
  • Standard mounting options are
    dia12.5mm (mounted) - OD = dia12.5mm,Thickness=3.5mm,No Thread
    dia25mm (mounted) - OD = dia25mm,Thickness=3.5mm,No Thread
  • Mounted options can include non-threaded or threaded mounts
  • Custom mounting may be possible depending on quantity and mechanical requirements
Note
  • Please send the required size, quantity, mounting type, and product link before ordering.
Request Raw Data

Yes. You may request the transmission curve or related spectral data for engineering review.

Copy the link of the product page and send email to shop@syronoptics.com, you will get reply within 1 working days.
Shipment & Delivery

We ship optical products to most supported regions, with shipping cost and delivery method confirmed before payment.

Shipping cost
  • Shipping is generally USD 5–40 per parcel
  • Orders above USD 300 are eligible for free shipping
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  • We generally ship to Europe, North America, Asia, the Middle East, and Oceania
  • Some countries may be unavailable depending on logistics or customs conditions
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  • After shipment, delivery time depends on destination and shipping method
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Note
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Payment & Quotation

You can order online, request a quotation, or use bank transfer depending on your purchasing process.

Can I request a quotation before ordering?
  • Yes, formal quotations are available before payment
  • Recommended for company purchases, larger quantities, custom sizes, or special shipping requirements
  • Please send the product link, quantity, destination country, and billing details if available
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  • Company purchase orders may be supported after confirmation
  • Please contact us before ordering if your organization requires PO processing, quotation, or invoice matching
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  • NET 7 or NET 30 terms may be available for eligible organizations
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  • Please contact us before ordering if you need NET payment terms
Import, Duties & Customs

mport duties, taxes, and customs handling depend on your destination country and shipping method.

Are duties and taxes included?
  • For express courier services such as DHL or FedEx, duties, taxes, and customs handling are usually paid by the buyer
  • The final import cost depends on destination country, declared value, and local customs rules
  • Duties and taxes are not included unless clearly confirmed before payment
Can SyronOptics help with import clearance?
  • Import-handled delivery may be available for selected regions
  • Supported regions may include USA, Canada, United Kingdom,Europe, Mainland China, Hong Kong, Singapore, Australia, and New Zealand
  • With import-handled delivery, we help arrange clearance and local delivery
  • This option may be slower than express courier
Note
  • If you are not sure, please contact us to confirm whether import-handled delivery is supported in your region.

This LP675 longpass filter is designed to transmit wavelengths longer than the cut-on region while reducing shorter-wavelength visible light. It is suitable for fluorescence imaging, optical inspection, and visible-band optical measurement systems where longer-wavelength signal needs to be separated from visible excitation or shorter-wavelength background. It helps separate longer-wavelength emission from shorter-wavelength excitation and reduce visible background interference.

Key specifications:

  • Wavelength / main spec: 675 nm cut-on wavelength
  • Bandwidth / transition spec: See specification table for transition characteristics
  • Transmission / blocking: T>85% from 685-1750 nm ;  OD5 from 200-665 nm
  • Format / custom option: Available in 25.4 mm diameter and 60x60mm, mounting options
LP675 Longpass Filter - Chlorophyll Fluorescence Imaging (Plant Health)

LP675 Longpass Filter - Chlorophyll Fluorescence Imaging (Plant Health)

Chlorophyll Fluorescence Imaging (Plant Health)

This is one of the most common uses for a cut-on wavelength of 675nm.

  • The Science: Chlorophyll $a$ absorbs blue and red light and re-emits (fluoresces) faint light at approximately 685nm (peak 1) and 730nm (peak 2).
  • How the Filter Works: The filter blocks the powerful red excitation light (usually <660nm) used to drive the photosynthesis but passes the faint fluorescence emission (>680nm) to the detector.
  • Why OD5 is needed: The fluorescence signal is very weak. You need Optical Density 5 (100,000x blocking) to ensure the bright excitation light does not overwhelm the sensor.

Compatible Light Sources

A. Excitation Sources (Light the filter MUST BLOCK)

  • Deep Red LEDs (630nm - 650nm): This is the ideal match. A high-power 640nm LED is perfect for exciting Chlorophyll or Alexa Fluor 660. The filter will block the LED light, leaving only the fluorescence.
  • Helium-Neon Laser (633nm): Standard gas laser. The filter blocks this line effectively (OD5).
  • Red Diode Lasers (635nm - 640nm): Common in pointers and industrial modules.
  • Warning on 660nm LEDs: A standard "660nm" LED often has a spectral width of ±20nm. This means the "tail" of the LED emission could bleed past 665nm and leak through the filter. If you use a 660nm source, you need a Shortpass Excitation Filter (e.g., SP660) in front of the light source to "clean up" the tail.

B. Transmissive Sources (Light the filter MUST PASS)

If you are using this for machine vision (surveillance, sorting) or backlighting:

  • NIR LEDs (730nm, 850nm, 940nm): The filter will pass >90% of this light.
  • 1064nm Nd:YAG Laser: The filter passes this wavelength (up to 1750nm limit), making it useful as a "laser line clean-up" filter that removes visible flashlamps or aiming beams while passing the infrared laser.
LP675 Longpass Filter - Deep Red / NIR Fluorescence Microscopy

LP675 Longpass Filter - Deep Red / NIR Fluorescence Microscopy

Application: Deep Red / NIR Fluorescence Microscopy

In life sciences, this filter serves as an Emission Filter for dyes that fluoresce in the far-red/Near-Infrared (NIR) window.

  • Target Fluorophores:Cy5.5: Excitation ~675nm / Emission ~694nm. (Note: This filter is tight for Cy5.5 excitation; see light sources below).Alexa Fluor 660: Excitation ~663nm / Emission ~690nm.Alexa Fluor 680: Excitation ~679nm / Emission ~702nm.IRDye 680: Excitation ~680nm / Emission ~694nm.

Recommended Light Sources

  • High-Power 640nm LED: This is the industry standard for this region. It is safely blocked by the LP675 filter (which blocks up to 665nm).
  • 635nm - 640nm Laser: Lasers have a very narrow spectral line, ensuring no light "leaks" past the 665nm blocking edge.

Similar Bandpass Filters

Product Faqs

Cut-on / cut-off wavelength

Cut-on / cut-off wavelength is the transition point where an edgepass filter starts or stops transmitting light; in a practical system, it defines which wavelength range is allowed through and which range is reduced or blocked.
Blocking region

Blocking region is the wavelength range where the filter is designed to suppress unwanted light; in a practical system, stronger or wider blocking helps reduce background signal, stray light, and detector interference.
Optical Density (OD)

Blocking depth / optical density (OD) describes how strongly unwanted light is suppressed in the blocking region; for example, OD6 @ 200–1200nm means the filter is designed to block wavelengths from 200–1200nm to about 0.0001% transmission, helping reduce stray light, background signal, and detector overload.
Angle of incidence (AOI)

Angle of incidence (AOI) is the angle at which light hits the filter surface; as AOI increases, interference filters can show a spectral shift, usually moving the transmission or transition wavelength toward shorter wavelengths.

Need Help Confirming This Filter?

Whether you are replacing an existing part or building a new system, send us:
- Original part number or target specification
- Required size and quantity
- Application or system goal

We will help check product fit or suggest a stock/custom alternative.