Doublet lens: a complete guide

The complexity of optical elements comes from the difference between simplified elements used for simulation and real optical elements that comes with limitation and defaults. Doublets are a way to minimise some optical default in your optical system, lets learn more about them.

If you are looking for more details, kindly visit yanggu.

What is a doublet lens ?

A doublet lens is a assembly of two lenses of different material cemented together.

Every optical material is subject to chromatic dispersion, defined by their Vd value. This chromatic dispersion will cause scattering of a signal at different wavelengths.

The objective of manufacturing a doublet lens is two use to “complementary” dispersing material to compensate the chromatic dispersion and have a resulting doublet lens with identical focusing power on it’s whole wavelength range.

These lenses are also called : achromatic lens, meaning lens with no chromatic dispersion, achromatic doublet is also a common name.

How to you make an achromatic doublet ?

Achromatic doublets are usually made out of two kinds of glass : Flint glass and Crown glass. A concave lens will be made usually in Flint glass and a convex lens in Crown glass with similar radius of curvature so they can easily be cemented together.

Flint glass are high refringent glass, meaning that they will cause a high scattering of light rays according to their wavelength. While Crown glass are low dispersion glass. It is easy to find is a glass is Flint or Crown as its name will include a “F” for Flint or a K for Crown (for example in the most common : N-BK7 ( Schott) or H-K9L (CDGM).

Cementing of the two lenses to form the doublet, is done with very thin, optically neutral glue material and hardened with UV light. Positioning of both lenses during the cementing and the hardening of the cementing medium is the key factor to the success of the manufacturing of the achromatic lens.

In order to increase optical transmission of the lens, it is not unusual to have a antireflect coating added on external surfaces after the cementing.

What is the purpose of achromatic doublet ?

Doublets improve the optical quality of a lens reducing both chromatic dispersion and spherical aberration. Their were first discovered in the XVIII century in England for telescopes applications.

Currently many imaging applications in the visible are using doublets :

• Astronomy
• Endoscopy
• Microscopy
• Photography

How to buy an doublet lens ?

Designing of a a doublet lens is not very difficult but need the experience of an optician to better understand the material possibilities and define the surface shapes of the two optics.

Design deliverable will be a separate drawing including optical glass selection for each component and eventually an assembly drawing of the doublet that will state the coating requirements and may also request blackening of the doublet edge.

Once the design completed, precision optics manufacturers with the experience and ability to assemble doublet lenses, will be able to quote for its manufacturing.

Cookies Policy

This cookie notice provides information about the types of cookies INDIZEN OPTICAL TECHNOLOGIES SL uses and why we use them. Your access to, and use of, the Site http://www.iotlenses.com. We inform you about our cookies Policy.

WEBSITE OWNER

Thank you for accessing the Site http://www.iotlenses.com which is owned and operated by:

Website Owner: INDIZEN OPTICAL TECHNOLOGIES SL - CIF B- IOT
Postal Address: C/Suero de Quiñones 34-36. , Madrid (Madrid), España
Contact: : 91 833 - :
Activity: Innovation in lenses

WHAT ARE COOKIES?

Cookies are small files that web pages, online stores, intranets, online platforms or similar, store in the browser of the user who visits them and are necessary to provide innumerable advantages to web browsing in the provision of interactive services.

The following information on the possible types of cookies helps to better understand the functions they make possible:

• Session cookies: these are temporary cookies that remain in the cookie space of your computer until you close the browser, so that none is recorded on the user's disk. The information obtained through these cookies serves to enable operational management with each of the users who are simultaneously accessing the web.
• Persistent cookies: these are cookies that remain stored in the cookie space of your computer once the browser is closed, and that you will consult this web page again the next time you access it to remember information that facilitates navigation (directly access the service without need to do the login process) or the provision of a commercial service (offer those products or services related to previous visits).

The cookies exchanged when browsing a web page can be:

• First-party or own cookies: these are cookies generated by the website that is being visited.
• Third-party cookies: these are cookies that are received when browsing that web page, but that have been generated by a third service that is hosted on it. An example may be the cookie used by an advertisement or advertising banner found on the web page we visit. Another may be the cookie used by a visitor counter hired by the website we visit.

Cookies can be used to:

• Technical purposes: they are also called "strictly necessary". They allow the user to navigate through a web page, platform or application and use the different options or services that exist in it, such as, for example, controlling traffic and data communication, identifying the session, access parts of restricted access, remember the elements that make up an order, carry out the process of purchasing an order, make the request for registration or participation in an event, use security elements while browsing, store content for the dissemination of videos or sound or share content through social networks .
• Personalization: they make it possible for each user to configure aspects such as the language in which they want to view the web page, display formats, etc.
• Analysis or performance: they allow us to measure the number of visits and navigation criteria of different areas of the web, application or platform and allow us to elaborate navigation profiles of the users of said sites, applications and platforms, in order to introduce improvements based on the analysis of the use data collected by users of the service.
• Advertising: they allow the implementation of efficiency parameters in the advertising offered on the web pages.
• Behavioral advertising: they allow the implementation of efficiency parameters in the advertising offered on the web pages, based on information about the behavior of the users obtained through the continuous observation of their browsing  habits, which allows the development of a specific profile. {co to display advertising based on it.

WHICH COOKIES DO WE USE?

ANALYTICS COOKIES - Google Tag Manager

Description:
These allow us to recognize and count the number of users of our Sites and understand how such users navigate through our Sites.  

Use:

• We use Google Analytics, and you can see below for how to control the use of cookies by Google Analytics.
• This helps to improve how our Sites works, for example, by ensuring that users can find what they are looking for easily.

ANALYTICS COOKIES - Hubspot

Description: HubSpot cookies are used to track visitors and understand their behavior on our Sites. This helps us to better engage with our users and improve their experience.

If you are looking for more details, kindly visit Double Concave Lenses Exporter.

Use: We use HubSpot to analyze user interactions with our Sites and to optimize our marketing efforts. HubSpot cookies allow us to:

• Track visitor activity and behavior on our Sites.
• Identify repeat visitors and their preferences.
• Enhance the user experience by providing personalized content.
• Measure the effectiveness of our marketing campaigns.

SOCIAL NETWORK

Description:
Social network cookies to register are used to link the web profile in the aforementioned social network. 

Use:

• You can use this button to redirect to the profile of your account IOT on LinkedIn, YouTube, Instagram and Facebook.

THIRD PARTY COOKIE

Additionally, IOT has a presence in portals and third-party services for which, if you want to know the privacy conditions and use of cookies, you should consult the policies provided by them:

• Facebook: https://facebook.com/help/cookies
• Linkedin: http://www.linkedin.com/legal/privacy-policy
• Instagram: https://www.facebook.com/policies/cookies/
• Youtube: https://www.google.es/intl/es/policies/technologies/cookies/

ACCEPT COOKIE POLICY

IOT offers information about its Cookies Policy at the bottom of the website.

With this information you can carry out the following actions:

• Accept cookies: this notice will not be displayed again when you enter the website again.
• Reject cookies: this notice will not be displayed again when entering the website again.
• Cookie settings: you can obtain more information about the cookies we use, read the Cookies Policy of IOT and modify the configuration to block cookies from IOT at any time. In the case of blocking cookies, the functionality of the Web may be reduced.

HOW TO DISABLE COOKIES?

Non-mandatory cookies may be disabled by adjusting the settings of the Website.

Said settings are located at the bottom of the Website. Furthermore, all browsers may be modified to disable the cookies configuration.

This is why most browsers offer the possibility to administer cookies: in order to allow for a more accurate control of privacy. Said settings may be located in the “options” or “preferences” section of the browser’s menu.

Find below links to disable cookies on each browser:

Internet Explorer (https://goo.gl/iU2wh2)

• In the tools menu, select “Internet options”.
• Click on the privacy tab.
• You may configure privacy with a six-position cursor which enables you to control the cookies which will be installed: Block all cookies, High, Medium High, Medium (default level), Low and Accept all cookies.

Mozilla Firefox (http://goo.gl/QXWYmv)

• Click the Tools menus at the top of the Firefox window.
• Select Options.
• Select the Privacy panel.
• You may choose Use a customized configuration of your browsing history and other options related to your privacy.

Google Chrome (http://goo.gl/fQnkSB)

• Click on the menu located on the toolbar.
• Select Settings.
• Click on Show advanced options.
• In the “Privacy” selection, click on the Content Settings button.
• You may configure the options in the Cookies selection.

Safari (https://support.apple.com/es-es/HT)

• Select the “Preferences” option in the settings menu.
• Open the privacy tab.
• Select the desired option in the “block cookies” section. ()
• Remember that you may not be able to use certain functions of the Website after disabling cookies.

If you do not wish to be tracked by cookies, Google has developed a complement which may be installed on your browser. Find it here: http://goo.gl/up4ND.

COOKIES ON MOBILE DEVICES?

The holder of the Website http://www.iotlenses.com also uses cookies and other storage means on mobile devices.

Cookies which are not mandatory to navigate this Website http://www.iotlenses.com may be disabled by entering “Set cookies on the button below to the right”.

These settings are located at the bottom of the Website http://www.iotlenses.com. Furthermore, as in the case of computer browsers, it is possible to disable or eliminate cookies by changing the options or settings in mobile device browsers.

If you wish to change the privacy options, follow the instructions of the developer of your mobile device browser. Find below a few examples of links you may use to modify privacy options on your mobile device.

• IOS: (http://goo.gl/61xevS)
• Windows : (https://goo.gl/tKyb0y)
• Chrome Mobile: (http://goo.gl/XJp7N)
• Opera Mobile: (http://goo.gl/Nzr8s7)

ACCEPTANCE OF COOKIES

This Website http://www.iotlenses.com does not install cookies on the Users’ devices prior to acceptance thereof by the Users.

We hereby inform you that if you reject the installation of cookies or disable these in your browser settings, certain services may not be available to you and therefore you may not be able to gain access to certain services and/or make full use of this Website http://www.iotlenses.com.

We last changed this policy on: July 16,

For more Narrow Bandpass Optical Filterinformation, please contact us. We will provide professional answers.