• Afganistan(USD $)
  • Afrika Selatan(USD $)
  • Albania(ALL L)
  • Aljazair(DZD د.ج)
  • Amerika Serikat(USD $)
  • Andora(EUR €)
  • Angola(USD $)
  • Anguila(XCD $)
  • Antartika(USD $)
  • Antigua & Barbuda(XCD $)
  • Antillen Belanda(USD $)
  • Arab Saudi(SAR ر.س)
  • Argentina(USD $)
  • Armenia(AMD Դ)
  • Aruba(AWG ƒ)
  • Australia(AUD AU$)
  • Austria(EUR €)
  • Azerbaijan(AZN ман)
  • Bahama(BSD BSD)
  • Bahrain(BHD .د.ب)
  • baju kaos(GBP £)
  • Bangladesh(BDT ৳)
  • Barbados(BBD BBD)
  • Belanda(EUR €)
  • Belarusia(USD $)
  • Belgium(EUR €)
  • Belize(BZD Be)
  • Benin(XOF Fr)
  • Bermuda(BMD BD$)
  • Bhutan(BTN Nu.)
  • Bolivia(BOB Bs.)
  • Bosnia & Herzegovina(BAM КМ)
  • Botswana(BWP P)
  • Brazil(USD $)
  • Britania Raya(GBP £)
  • brunei(BND B$)
  • Bulgaria(EUR €)
  • Burkina Faso(XOF Fr)
  • Burundi(BIF ₣)
  • Ceko(CZK Kč)
  • Chad(XAF ₣)
  • Chili(USD $)
  • Cina(CNY ¥)
  • Denmark(DKK kr)
  • Djibouti(DJF ₣)
  • Dominika(XCD $)
  • Ekuador(USD $)
  • El Salvador(USD $)
  • Eritrea(ERN Nfk)
  • Estonia(EUR €)
  • Eswatini(USD $)
  • Etiopia(ETB Br)
  • Fiji(FJD FJ$)
  • Filipina(PHP ₱)
  • Finlandia(EUR €)
  • Gabon(XOF Fr)
  • Gambia(GMD D)
  • Georgia(USD $)
  • Georgia Selatan & Kepulauan Sandwich Selatan(GBP £)
  • Ghana(GHS ₵)
  • Gibraltar(GBP £)
  • Grenada(XCD $)
  • Guadeloupe(EUR €)
  • Guam(USD $)
  • Guatemala(GTQ Q)
  • Guernsey(GBP £)
  • Guinea(GNF ₣)
  • Guinea ekuator(XAF ₣)
  • Guinea-Bissau(XOF Fr)
  • Guyana(GYD $)
  • Guyana Perancis(EUR €)
  • Haiti(USD $)
  • Honduras(HNL L)
  • Hong Kong SAR(HKD HK$)
  • Hungaria(HUF Ft)
  • India(INR ₹)
  • Indonesia(IDR Rp)
  • Irak(USD $)
  • Irlandia(EUR €)
  • Islandia(ISK Kr)
  • Israel(ILS ₪)
  • Italia(EUR €)
  • Jamaika(JMD $)
  • Jepang(JPY ¥)
  • Jerman(EUR €)
  • Kaledonia Baru(XPF ₣)
  • Kamboja(KHR ៛)
  • Kamerun(XAF ₣)
  • Kanada(CAD $)
  • Kazakstan(KZT 〒)
  • Kenya(KES Sh)
  • Kepulauan Cocos (Keeling)(AUD AU$)
  • Kepulauan Cook(NZD $)
  • Kepulauan Falkland(FKP FKP)
  • Kepulauan Faroe(DKK kr)
  • Kepulauan Mariana Utara(USD $)
  • Kepulauan Pitcairn(NZD $)
  • Kepulauan Terluar AS(USD $)
  • Kepulauan Turks & Caicos(USD $)
  • Kepulauan Virgin Inggris(USD $)
  • Kirgistan(KGS С̲)
  • Kiribati(AUD AU$)
  • Kolumbia(USD $)
  • Komoro(KMF Fr)
  • Kongo - Brazzaville(XAF ₣)
  • Kongo - Kinshasa(CDF ₣)
  • Korea Selatan(KRW ₩)
  • Kosta Rika(CRC ₡)
  • Kota Vatikan(EUR €)
  • Kroasia(EUR €)
  • Kuwait(KWD دينار)
  • Laos(LAK ₭)
  • Latvia(EUR €)
  • Lesotho(USD $)
  • Libanon(LBP ل.ل)
  • Liberia(USD $)
  • Libya(USD $)
  • Liechtenstein(CHF ₣)
  • Lithuania(EUR €)
  • Luksemburg(EUR €)
  • Macao SAR(MOP P)
  • Madagaskar(USD $)
  • Makedonia Utara(MKD ден)
  • Maladewa(MVR ރ.)
  • Malawi(MWK MK)
  • Malaysia(MYR RM)
  • mali(XOF Fr)
  • Malta(EUR €)
  • Maroko(MAD د.م.)
  • Martinik(EUR €)
  • Mauritania(USD $)
  • Mauritius(MUR ₨)
  • mayotte(EUR €)
  • Meksiko(USD $)
  • Mesir(EGP E£)
  • Mikronesia(USD $)
  • Moldova(MDL L)
  • Monako(EUR €)
  • Mongolia(MNT ₮)
  • Montenegro(EUR €)
  • Montserrat(XCD $)
  • Mozambik(USD $)
  • Myanmar (Birma)(MMK K)
  • Namibia(USD $)
  • Nauru(AUD AU$)
  • Nepal(NPR ₨)
  • Nigeria(NGN ₦)
  • Nigeria(XOF Fr)
  • Nikaragua(NIO C$)
  • Niue(NZD $)
  • Norway(USD $)
  • Oman(OMR ر.ع.)
  • pakistan(PKR ₨)
  • Palau(USD $)
  • Panama(USD $)
  • Pantai Gading(XOF Fr)
  • Papua Nugini(PGK K)
  • Paraguay(PYG ₲)
  • Perancis(EUR €)
  • Peru(PEN S/)
  • Polandia(PLN zł)
  • Polinesia Perancis(XPF ₣)
  • Portugal(EUR €)
  • Puerto Riko(USD $)
  • Pulau Aland(EUR €)
  • Pulau Ascension(SHP £)
  • Pulau Bouvet(USD $)
  • Pulau cayman(KYD $)
  • Pulau manusia(GBP £)
  • Pulau Marshall(USD $)
  • Pulau Mendengar & McDonald(AUD AU$)
  • Pulau Natal(AUD AU$)
  • Pulau Norfolk(AUD AU$)
  • Pulau Solomon(SBD Si$)
  • Qatar(QAR ر.ق)
  • Republik Afrika Tengah(XAF ₣)
  • Republik Dominika(DOP $)
  • Reuni(EUR €)
  • Rumania(RON L)
  • Rusia(RUB р.)
  • Rwanda(RWF ₣)
  • Sahara Barat(MAD د.م.)
  • Samoa(WST T)
  • Samoa Amerika(USD $)
  • San Marino(EUR €)
  • Sao Tome & Principe(USD $)
  • Selandia Baru(NZD $)
  • Senegal(XOF Fr)
  • Serbia(RSD din)
  • Seychelles(USD $)
  • Sierra Leone(SLL Le)
  • Singapura(SGD S$)
  • Siprus(EUR €)
  • Slovenia(EUR €)
  • Slowakia(EUR €)
  • Somalia(SOS Sh)
  • Spanyol(EUR €)
  • Srilanka(LKR Rs)
  • St Helena(SHP £)
  • St Kitts & Nevis(XCD $)
  • St Vincent & Grenadines(XCD $)
  • St. Lucia(XCD $)
  • St. Martin(EUR €)
  • St. Pierre & Miquelon(EUR €)
  • Sudan(SDG ج.س.)
  • Suriname(USD $)
  • Svalbard & Jan Mayen(USD $)
  • Swedia(SEK kr)
  • Swiss(CHF ₣)
  • Taiwan(TWD NT$)
  • Tajikistan(TJS ЅМ)
  • Tanah penggembalaan(DKK kr)
  • Tanjung Verde(CVE $)
  • Tanzania(TZS Sh)
  • Thailand(THB ฿)
  • Timor-Leste(USD $)
  • Tokelau(NZD $)
  • Tonga(TOP T$)
  • Trinidad & Tobago(TTD TTD)
  • Tristan da Cunha(GBP £)
  • Tunisia(USD $)
  • Turki(USD $)
  • Turkmenistan(TMT m)
  • Tuvalu(AUD AU$)
  • Uganda(UGX Sh)
  • Ukraina(UAH ₴)
  • Uni Emirat Arab(AED د.إ)
  • Untuk pergi(XOF Fr)
  • Uruguay(UYU $)
  • Uzbekistan(UZS лв)
  • Vanuatu(VUV Vt)
  • Venezuela(USD $)
  • Vietnam(VND ₫)
  • Virgin Islands(USD $)
  • Wallis & Futuna(XPF ₣)
  • Wilayah Palestina(ILS ₪)
  • Wilayah Samudra Hindia Britania(USD $)
  • Wilayah Selatan Prancis(EUR €)
  • Yaman(YER ﷼)
  • Yordania(USD $)
  • Yunani(EUR €)
  • Zambia(USD $)
  • Zimbabwe(USD $)
/ /

What is a Longpass Coated Optical Filter? A Complete Guide for Buyers

May 15,2026 | JINGYU OPTOELEC

What is a Longpass Coated Optical Filter

A Longpass Filter acts like a gatekeeper for light. It allows light waves longer than a specific wavelength (e.g., 640nm) to pass through freely, while blocking or reflecting shorter wavelengths (e.g., blue or UV light).

Think of it as a “optical sieve.” If you want only red or infrared light for hair removal or a red stage effect, a longpass filter gives you that pure, targeted light.

How Does It Work? The Magic of Optical Coating

The secret lies not in the glass itself, but in the **thin-film coating** applied to its surface.

The Process: Using vacuum deposition technology, dozens of nano-scale layers are coated onto high-quality glass (e.g., Schott glass or K9 optical glass).
The Principle (Interference): These layers are precisely designed to create light interference – canceling out unwanted short wavelengths while boosting the transmission of the desired long wavelengths.
The Result: A filter with>95% peak transmittance and sharp cut-off characteristics, ensuring high brightness and purity of light.

✅ No advanced coating process = no reliable longpass filter.

Key Specifications You Must Know (For Custom Orders)

When choosing or customizing a longpass filter, focus on these 4 parameters:

Specification What It Means in Plain English
Cut-On / Cut-Off Wavelength The “dividing line.” e.g., 640nm longpass = allows light longer than 640nm (orange/red) to pass.
Transmittance How much useful light gets through. >90%-95% is excellent for bright, efficient devices.
Blocking / Cut-Off Depth How well it blocks the short, unwanted light. OD2 (1% transmission) to OD4 (0.01%) are common.
Surface Quality (Scratch/Dig) The smoothness of the glass surface (e.g., 40/20 or 60/40). Affects clarity and lifespan.

Top 5 Filter Applications

They are not just lab equipment; they are key components in everyday devices.

1. Beauty & Aesthetic Devices (IPL/Hair Removal)
Goal: Remove hair, acne, or vascular lesions.
How it works: LP640nm / LP690nm longpass filters allow deep-penetrating infrared light to target hair follicles while blocking harmful UV/short blue light.

2. Stage & Entertainment Lighting
Goal: Create vivid, pure colors (red, orange, deep amber).
How it works: Moving heads, pattern projectors, and laser lights use longpass filters to cut off blue/green light, leaving only saturated reds and warm tones.

3. Laser Systems (e.g., 10.6µm CO2 lasers, 1064nm)
Goal: Combine or clean up laser beams.
How it works: Longpass filters can reflect a 532nm green aiming beam while passing a 1064nm infrared cutting beam – critical for safety and precision.

4. Machine Vision & Industrial Inspection
Goal: Enhance contrast for defect detection.
How it works: A longpass filter blocks ambient light but allows the specific color of a laser or LED signal to reach the camera sensor.

5. Security & Surveillance (Night Vision)
Goal: See clearly in darkness.
How it works: During the day, the filter blocks IR light for true colors. At night, it passes IR light from illuminators for clear black-and-white images.

Available Materials & Customization

Depending on your application (power, heat, wavelength range), you can choose the base glass:

Glass Material Best For Key Benefit
K9 (Optical Glass) Stage lights, general instruments Cost-effective, good optical performance
Schott Glass High-end medical/beauty devices Superior clarity and thermal stability
Fused Silica High-power lasers, UV to IR applications Extremely wide transmission range, very low thermal expansion
Sapphire Extreme environments (military, high-power) Very hard, scratch-resistant, high thermal conductivity

Custom Options:

  • Thickness: 0.21mm to 2.0mm (ultra-thin available)
  • Size: Any diameter or square shape (e.g., D20mm, 25x25mm)
  • Coating: AR coating on non-filter side to reduce reflection (up to 98% transmission)
  • Color & Logo: Custom silk-screen printing or UV ink logos

Why Choose a Professional Manufacturer

To ensure stable quality and reliable performance, choose a supplier with:

  • In-house coating machines (not just cutting/assembling)
  • Complete process chain: Cutting → Grinding → Polishing → Cleaning → Coating → Assembly → Inspection → Packaging
  • Testing equipment: Spectrophotometer to provide transmission curve reports with each batch
  • Cleanroom environment: Class 1000 or better for coating and assembly
  • Low MOQ and custom service: Flexible for prototypes or mass orders

A supplier without in-house coating cannot control the most critical part of a longpass filter.

Quick Summary

Question Answer
What does a longpass filter do? Allows long wavelengths (e.g., red/IR) through; blocks short ones (blue/UV).
Where is it used? IPL hair removal, stage lights, lasers, machine vision, night vision.
What specs matter most? Cut-on wavelength, transmittance (>90%), blocking depth.
Can I customize size/wavelength? Yes, most suppliers offer full customization with low MOQ.

Contact Us for Your Custom Longpass Filter

Whether you need a 640nm longpass filter for an IPL beauty device, a high-power laser beam combiner, or a stage lighting color filter, we can manufacture to your exact specifications.

✅ OEM/ODM Welcome  
✅ ISO Certified Facility  
✅ Free Technical Support  
✅ Fast Sample Delivery

Komentar

Nama
Email
Komentar