BP525-20 Bandpass Filter(CWL=525nm,FWHM=20nm)
BP525-20 Bandpass Filter(CWL=525nm,FWHM=20nm)
PartNumber:SO3010239
In Stock.
Ships within 5 working days of order.
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- Wavelength: Center wavelength 525nm with 20nm FWHM bandwidth for green spectrum transmission
- Spectral Features: Narrow bandwidth with steep edge transitions for precise spectral isolation
- Optical Density: OD6+ blocking outside passband ensures exceptional background suppression
- Filter Dimension Availability: Available in standard round and square formats to fit common optical mounts
Request Raw Data
Request Raw Data
You can request the raw transmission data from us.
Copy the link of the product page and send email to shop@syronoptics.com, you will get reply within 1 working days.
Shipment & Delivery
Shipment & Delivery
- Stocked products ship within 5 business days after order confirmation.
- Custom-made products typically ship within 4–8 weeks.
- Delivery times may be affected by holidays, customs clearance, or other unforeseen events.
- Tracking information becomes available 3–5 days after dispatch when the parcel is handed to the local courier.
- Some deliveries may require customer pickup. Please ensure your contact information is correct and respond promptly to courier communications.
- General international parcel shipping cost: USD 35 (for reference).
Return & Refund
Return & Refund
1. Eligible Products
Stocked (catalog) products with a unit price under USD 500 are eligible for return within 14 days after delivery.
Custom-made or non-stock items are not eligible for no-reason returns.
2. No-Reason Return (Buyer’s Remorse)
If you wish to return an item for reasons other than product defect or seller error:
- Please email shop@syronoptics.com to request a return authorization and return address.
- Buyer is responsible for all return shipping costs.
- Items must be unused, in original condition, and with original packaging.
- Refund will be issued after inspection of the returned item.
3. Seller’s Fault (Defective / Wrong / Damaged Item)
If the return is due to seller error (defective product, wrong item shipped, or damage during shipping):
Please provide clear evidence (photos or videos) showing the issue.
We will evaluate the case and either:
- Provide a replacement, or
Issue a refund (with or without requiring the item to be returned). - Return shipping cost will be covered by the seller in confirmed seller-fault cases.
4. Important Notes
- Returned items are subject to inspection before refund approval.
- Shipping fees, customs duties, and taxes are non-refundable unless the return is due to seller fault.
- Unauthorized returns will not be accepted.
Custom Sizing
Custom Sizing
Custom sizing is available from 3 × 3 mm (or Ø5 mm) up to 60 × 60 mm. For custom cut sizes, please contact shop@syronoptics.com for a quotation.
Pricing is not significantly lower for small-size orders in low quantities due to operational costs.
Payment Terms
Payment Terms
Payments can be made online using Credit Card, Apple Pay, Google Pay, WeChat Pay, and Alipay.
If you prefer to pay by bank transfer, please contact shop@syronoptics.com to request an invoice with our banking details.
If you require deferred payment terms, you may request NET 7 or NET 30 at the time of placing your order.
All requests for deferred payment are subject to approval and will be confirmed by SyronOptics via email.

| Part Number | |
|---|---|
PN |
SO3010239
|
| Optical Specification | |
Center Wavelength |
525nm
|
FWHM |
20nm
|
Optical Density |
OD6@200-1100nm
|
Curve Transmission Curve from last batch production.
(Performance may vary from batch to batch)
(Zero Value is not shown in the graph)
(Regular Testing Region from 200-1200nm)
|
|
-
BP525-20 Bandpass Filter - Fluorescence Microscopy (Emission Filter)
Fluorescence Microscopy (Emission Filter)
This is the most common use. 525 nm is the peak emission wavelength for many popular green fluorescent dyes and proteins. The OD6 blocking is critical here to block the bright excitation light so the camera detects only the faint fluorescence.
- Target Fluorophores: GFP (Green Fluorescent Protein), FITC (Fluorescein), Alexa Fluor 488, Cy2, and SYBR Green.
Recommended Light Sources
To use this filter effectively, your light source must emit energy within the 515–535 nm range.
- High-Power Green LEDs (Recommended): Look for LEDs with a peak wavelength of 520 nm, 525 nm, or 530 nm. These are the ideal match for this filter.
- Laser Diodes (520 nm): Direct green laser diodes (often 520 nm) fit perfectly within the passband.
- DPSS Lasers (532 nm): A 532 nm green laser is common, but it sits right at the edge of this filter's 20 nm bandwidth (515–535 nm). It will pass, but you might lose some intensity if the filter's angle isn't perfect. A slightly wider filter (e.g., BP525-25 or BP532) is usually preferred for 532 nm lasers, but BP525-20 can work.
- Broadband Sources (Xenon/Mercury Arc): Only if used with a corresponding excitation filter to stimulate fluorescence.
-
BP525-20 Bandpass Filter - Machine Vision & Imaging
Machine Vision & Imaging:
Used to increase contrast in industrial inspection. A narrow 20 nm bandwidth effectively blocks ambient sunlight and overhead lighting, allowing the camera to see only the light from a structured green LED source.
-
BP525-20 Bandpass Filter - Laser Clean-up
Laser Clean-up
It can be used to "clean up" the output of a laser, ensuring only the 525 nm line passes through, removing spectral noise.
The specific required light sources are:
- 520 nm Direct Diode Laser: This is the ideal source. It sits comfortably in the middle of the filter's range, ensuring maximum transmission while the filter strips away any "wings" or spontaneous emission noise.
- 532 nm DPSS Laser: This is the most common green laser. It fits within the filter's passband (which ends at roughly 535 nm), effectively removing the infrared pump light (typically 808 nm or 1064 nm) that often leaks through these lasers.
Fequently Asked Questions
Different Types of Filter Mountings
Unmounted:
- a bare glass optical filter
Mounted:
- Smooth Mount for protection of the optics. No thread is there on the mount.
Metric Mount:
- Start with M as prefix, usually seens as M25.5x0.5mm. Mostly used as camera filters
Imperial Mount:
- Start with SM as prefix, usually seen SM1, SM05 etc... Mostly used in Optical system. (You will have a SM external thread to connecting to other objects)
C-Mount:
- Very frequently used mounting. C-Mount is 1‘’-32TPI. And it is not the same thing as SM1, or M25.5x0.5mm.
What are the Thickness of the Optical Filters?
For Unmounted Optics:
- 0.5mm
- 1.1mm
- 2.0mm
*Most of our optics are coming with 1.1mm and 2.0mm
With Standard Mounting (Mounted, No Thread):
- 3.5mm (Default)
- 6mm (Upon Request)
Thread Mounted:
- 6mm - 8mm
-
dia12.5mm(unmounted)
Clear Aperture:
>90%
Mounting Thickness:
n.a
Internal/External Thread:
n.a/n.a
-
dia12.5mm(mounted)
Clear Aperture:
dia9mm
Mounting Thickness:
3.5mm
Internal/External Thread:
n.a/n.a
-
dia25mm(mounted)
Clear Aperture:
dia21mm
Mounting Thickness:
3.5mm
Internal/External Thread:
n.a/n.a
-
dia25mm(unmounted)
Clear Aperture:
>90%
Mounting Thickness:
n.a
Internal/External Thread:
n.a/n.a
-
SM05(0.535″-40TPI)
Clear Aperture:
dia9mm
Mounting Thickness:
7.62mm
Internal/External Thread:
SM05/SM05
-
SM1(1.035″-40TPI)
Clear Aperture:
dia21mm
Mounting Thickness:
7.62mm
Internal/External Thread:
SM1/SM1
-
C-Mount(1″-32TPI)
Clear Aperture:
dia21mm
Mounting Thickness:
Internal/External Thread:
C-Mount/C-Mount
-
M25.5x0.5mm(mounted)
Clear Aperture:
dia20.5mm
Mounting Thickness:
6.5mm
Internal/External Thread:
M25.5x0.5mm/M25.5x0.5mm
-
M27x0.5mm(mounted)
Clear Aperture:
dia22mm
Mounting Thickness:
6.5mm
Internal/External Thread:
M27x0.5mm/M27x0.5mm
-
M30.5x0.5mm(mounted)
Clear Aperture:
dia25.5mm
Mounting Thickness:
6.5mm
Internal/External Thread:
M30.5x0.5mm/M30.5x0.5mm
-
M34x0.5mm(mounted)
Clear Aperture:
dia29mm
Mounting Thickness:
6.5mm
Internal/External Thread:
M34x0.5mm/M34x0.5mm
-
M35.5x0.5mm(mounted)
Clear Aperture:
dia30.5mm
Mounting Thickness:
6.5mm
Internal/External Thread:
M35.5x0.5mm/M35.5x0.5mm
-
M37x0.5mm(mounted)
Clear Aperture:
dia32mm
Mounting Thickness:
6.5mm
Internal/External Thread:
M37x0.5mm/M37x0.5mm
-
M52x0.75mm(mounted)
Clear Aperture:
dia47mm
Mounting Thickness:
6.5mm
Internal/External Thread:
M52x0.75mm/M52x0.75mm
-
M55x0.75mm(mounted)
Clear Aperture:
dia50mm
Mounting Thickness:
6.5mm
Internal/External Thread:
M55x0.75mm/M55x0.75mm
-
dia27mm(unmounted)
Clear Aperture:
>90%
Mounting Thickness:
n.a
Internal/External Thread:
n.a/n.a
-
dia34mm(unmounted)
Clear Aperture:
>90%
Mounting Thickness:
n.a
Internal/External Thread:
n.a/n.a