Danish Laboratory for Technical Optics was founded as an institute under the Danish Academy of Technical Sciences.

The Laboratory was located at Danmarks Tekniske Højskole in Copenhagen. Danmarks Tekniske Højskole was the first university in Denmark to educate Engineers and was later renamed to the Technical University of Denmark.

The picture shows the building of Danmarks Tekniske Højskole (Polyteknisk Læreanstalt) at Østervoldgade in the center of Copenhagen, approx. 1900 when the building was built. This was the first home of the Danish Laboratory for Technical Optics 


Danish scientist Alfred Hermansen issues the first Danish books about optical thin film. In the same period, he designs and manufactures his first laser mirrors and manufactures his first laser in the cellars at The University of Copenhagen.

He later encourages Danish Laboratory for Technical Optics to make these coatings for the benefit of society.

The challenge was accepted! 

The picture shows a copy of Hermansen publication “A Theory of Interference Filters”, 1955 


The first Danish lasers were built by the Danish Laboratory for Technical Optics.

The laser mirrors were designed and manufactured inhouse.  

The picture is of the first bell coating machine.
As one can imagine, it was only possible to manufacture on a very limited surface and deposition control was 100% manual. 


Director of Danish Laboratory for Technical Optics Werner Olsen and Medical Doctor Jørgen Rygårds issue their ground-breaking paper regarding improved immuno-fluorescence microscopy based on replacing coloured glass with coated optical interference filters.

The same year, Jørgen Rygård proposes Carl Zeiss and Leitz (later Leica) to implement coated optical interference filters, which eventually both companies did. 

The picture shows the original report issued by Olsen & Rygård titled: Immunfluorescensmikroskopi med inteferensfiltre”, 1970. 


The Technical University of Denmark moves from the center of Copenhagen to brand new facilities in Lundtofte (some 15 km north of Copenhagen), and Danish Laboratory for Technical Optics moves along.

The first computer optimised filter designs are made, opening the market for fluorescence microscopy interference filters. 

The picture is of a summer lunch break shorty after the move to Lundtofte. Institute director Werner Olsen is second from the left. 


The current CTO of DOTF Henrik Fabricius is employed by the Danish Laboratory for Technical Optics.

After a few years Henrik starts his work in the Optical Thin Film area. 

The picture shows a young Henrik with his wife Bodil and their first son Esben. 


Danish Laboratory for Technical Optics is merged with Danish Light Laboratory to form Light & Optics – still an institute under the Danish Academy of Technical Sciences.

At the same time, the activities are moved to Hjortekær – just a few 100 meters from The Technical University of Denmark. 

Light & Optics contributed to solving many problems for Danish and international customers. The report is about design of a backlight system and shows the company logo of Ligth & Optics 


The first XYZ filters are created. Philips adapt these into a colour calibration device that revolutionized the calibration of CRT colour TV’s. 

The picture is a reprint of the DOPS-Nyt (Danish Optical Society newsletter) issued Dec 1996 and contains articles only about DELTA Light & Optics. 


DOTF’s first computer-controlled deposition system was created by cutting wires on the PCB on an existing Balzers coater and introducing our homemade electronics.

Henrik Fabricius creates the first DOS-based version of the Gradient Index Monitoring Program (GIMP).

Today, the Windows-based version of GIMP is the core of our proprietary optical monitoring system.


Danish Electronics, Light & Acoustics (DELTA) is founded by merging Light & Optics with Danish Acoustical Institute, and Elektronik Centralen.

The same year, the first version of our proprietary design software TYNDFILM (Thin Film in Danish) is created. 

The picture shows DELTA Light & Optics sales binders with the new DELTA logo.  


The first Leybold Optics Syros Pro machine Advanced Plasma Source coater is acquired and GIMP deposition control and optical monitoring are implemented.

Leybold Optics (now Bühler Leybold Optics) and Delta agreed to make a software interface allowing our GIMP software to control the deposition. 


The Light & Optics Division moves together with the rest of DELTA in a new build facility located in the DTU (Danish Technical University) Science Park in Hørsholm some 25 km north of Copenhagen. 


Poul Svensgaard joins DELTA as Senior Vice President with responsibility for the Light & Optics Division. 


Thin Film veteran and founder of Edinburgh Instruments and later founder of Edinburgh Biosciences Professor Des Smith proposes DELTA to create Continuous Variable Filters.

In the frame of the Eurostars project called Optitune, DELTA creates the its Continuous Variable LongWave Pass and Short-Wave pass filters.

Today, DOTF is the leading provider of CVF’s for applications in the UVA over the VIS to NIR wavelength range. 


Delta Optical Thin Film is created through a management buyout by Poul Svensgaard & Henrik Fabricius. The buyout was backed by the world leading supplier of Micro Plate Readers, BMG Labtech GmbH.

The involvement secured BMG Labtech exclusive rights to use our continuous variable filters for fluorescence-based micro plate readers. 

The picture shows from the right: Chairman of the Board Dr. Thomas Räbiger, CTO Henrik Fabricius, CEO Poul Svensgaard. 


Delta Optical Thin Film outgrows its previous facility and moves into its new purpose build factory – also located in the DTU Science Park in Hørsholm.

The new facility offers 2100 m2 of cleanroom and offices. The first magnetron sputter machine is acquired. 

The facility is designed with optimal workflow and sustainability in mind. The is covered with more than 1000 m2 of the most efficient solar panels offering a good carbon free contribution to our electricity consumption. 


Delta Optical Thin Film successfully helps numerous PCR instrument manufactures with advanced optical filters to increase the test capacity for COVID-19.  

The filters are manufactured on our new high capacity Helios 800 magnetron sputter coater and diced to smaller sizes.  Filters are most often supplied in vacuum trays to prevent particles from conventional packing material.