The document describes a new sulfur-based polymer material called the Brimstone LensTM that can be used for infrared optics. It has several advantages over traditional infrared materials like semiconductor crystals and chalcogenide glasses in that it is less expensive to produce, lighter weight, and can transmit infrared light from 0.7 to 6.7 microns. The material is flexible and can be easily molded into complex shapes without expensive grinding and polishing. It is produced through a novel organic synthesis and cross-linking process that gives it unique optical properties for applications like night vision goggles, infrared cameras, and automotive sensors.

1. Sulfur-based polymer material with infrared transmission from
~700 to 6700nm: SPIE paper 11403-18
Dr. Rinat Akhmetshin, Chief Science Officer with a PhD in chemistry
Brett Rosenberg, Chief Executive Officer & Point of Contact
(281) 785-6184 Brett@sempersystem.com

2. The Brimstone Lens™
Traditional Materials used in Infrared Optics
• Semiconductor Crystals and Chalcogenide Glasses
• Expensive
• Rare Semiconductor Materials
• Complex Manufacturing
• Toxic Chemical Synthesis
Brimstone Lens™ for Infrared Optics
• The density of the material with 70% sulfur content is 1.7g/㎤ compared to 5.3g/㎤ for
Germanium making the Brimstone Lens™ ~3 times lighter
• IR transmission ~ .7 to 6.7 micron and can be extended or narrowed
• Low cost, flexible, acts as an optical adhesive strongly attaching to everything except
silicone

3. The Brimstone Lens™
Properties
oPolymer material
• Flexible, can easily be molded, and hardens at room temperature
• This material is cast, allowing the production of optical elements of any shape, including
with any curvature (spherical, hemispherical, aspheric optics, Fresnel lenses, biased
optical center lenses etc.)
• This material eliminates the need for expensive grinding and polishing necessary in
today’s IR optical manufacturing

4. Unique Chemistry
• Highly precise organic synthesis of thionated polymers
• Comprised of one or more aromatic and sulfur groups through ring opening polymerization of
sulfur polymer selected aromatic substrates through a novel cross-linking strategy
• This material can be used as a matrix, a basis for creating a composite material with previously
unattainable characteristics. Namely, in the process of copolymer synthesis, to introduce in its
structure nanoparticles of germanium and silicon (IR-conductive metals).
• The resulting mixture can be placed in a magnetic field until polymerization is completed in
order to properly orient and evenly distribute the nanoparticles in the volume of the
polymer matrix. As a result, materials with new mechanical and optical properties can be
obtained

5. Existing IR Transparent Sulfur-rich Polymers
Type Technique Transparency
Sulfur-Rich Copolymer Inverse Vulcanization Near and MID-IR wavelengths
High-molecular-weight sulfur
polymer chains with 1,3-
diisopropylbenzene (DIB)
Co-polymerization Near IR
Drawback
o Presence of alkyl groups
• Intense absorption in the range of near IR
o Low glass-transition temperature

6. Brimstone Lens™
 Brimstone Lens™ polymer material can be produced sustainably and inexpensively on large scale with the ability to extend and narrow IR
transparency
 No requirement of rare and expensive semiconductor crystals or highly toxic chalcogenide glass manufacturing
 Can serve as a base for complex IR nanostructures with previously unattainable properties
 Demonstrates utility as an optical adhesive, except silicone
 Lighter weight and lower cost invites utility in applications such as
• Security and guidance systems
• Quality analyzers
• Infrared Cameras
• Night vision goggles and optics
• ADAS: Advanced Driver Assistance Systems

7. Air Force Research Lab, Wright-Patterson AFB
• your material is a little different than what I've seen in that it's very transparent from about a
micron to seven and a half, eight microns, also seems to have transparency out beyond 10
microns.
• clearly something about your cross-linking strategy is generating a different optical property set in
the SWIR to MWIR than the traditional DIB approach which is widely published on
• I’m interested in the area and it seems all of these sulfur polymer materials offer technological
potential for optics that would be of interest to the Air Force.

8. Preparation Processes
Scheme 1
 Oxidation of monomer or oligomer comprising one or more aromatic
groups
• oxidizing agents differ for different synthetic routes
• Examples
• Sodium peroxide
• 3-chloroperbenzoic acid
• Ammonium persulfate
• Oxygen or air comprising oxygen

9. Preparation Processes (contd..)
• The oxidization results in
• Compound having fully aromatic groups and quinoid fragments
• Capable of converting to an aromatic moiety when reacted with sulfur
• Or an unsaturated precursor of an aromatic compound
• Converts to an aromatic moiety when reacted with sulfur.
• Co-polymerization via double bonds of Carbon in Quinoid Fragments
• Results in reduction of quinoid groups to aromatic group
• Effect : Non-absorption in the near IR region

10. Preparation Processes (contd..)
 Schematic of the process
oThe aromatic oligomers interact with
oxygen in the air which leads to
formation of quinoid fragments

11. Preparation Processes (contd..)
 Schematic of the process
oQuinoid fragments are reactive towards sulfur
oThe process repeats for ‘n’ oligomers

12. Preparation Processes (contd..)
Scheme 2
 One or more oxidation steps may
be omitted if
• Oligomer contains one or more
quinoid fragments
• Structures comprise of one or more
quinoid fragments
 Reaction of a pre-oxidized
oligomer with sulfur to give
thionated polymer

13. Preparation Processes (contd..)
Scheme 2
 Sulphur Sources
• Elemental Sulphur
• Metal Sulphides
• Poly sulphide e.g. MSxH or M2Sx (M : Metal; x : 1 to 100)
• Compound that decomposes to elemental sulfur under heating e.g. S2O
• Compound that decomposes to elemental sulfur in the presence of alkali metal sulfides
e.g. hydrogen sulfide
• Compound that decomposes to elemental sulfur in the presence of an acid e.g. Na2S2O3

14. Preparation Processes (contd..)
 Treatment of Thionated Polymers
oUndesirable impurities are removed using
• Extraction : By using solvents e.g. chloroform, methylene chloride, etc. An extractor such
as the Soxlet Extractor may be used to facilitate the extraction.
• Filtration : method may be also or alternatively be utilized to remove impurities.
• Heating under vacuum : For unreacted sulfur and unreacted aromatic compounds
• Other methods : Specific sorbents, Ceramic Filters, Molecular Sieves
 Thionated Brimstone Lens™ is ready for use.

15. Example
• Sulfur (10 g) heated to ~120℃ while mixing on a magnetic
stirrer in an open glass container (diameter 2 cm) using an
octagonal teflon-covered magnetic stirring bar.
• After 3 hours, N-(-4-(naphthalen-1-ylimino)naphthalen-
1(4H)-ylidene)-4-(10H-phenothiazin-10-yl)naphthalen-1-
amine & (N,N’,N,N’)-N,N’-naphthalene-1,4-diylidene) bis(4-
(10H-phenothiazin-10-yl)naphthalen-1-amine) with a
molecular weight in the range of 597-1000 Dalton, (2 g), was
added to the sulfur over 30 minutes, and was thoroughly
ground in agate mortar. The mixture was heated with mixing
for about 5 hours, poured into aluminum foil, placed into
oven at 80 °C for 5 hours, and cooled to room temperature
over 3 hours. The film thickness was 2 +/- 0.1 mm
• Note that in the region of 0.67-6.2 μm, the transmittance of
the sample is 80-88%
• absorption bands are distorting the given range at 2.8-3.1
μm, 3.25-3.4 μm, and 3.85-4 μm.
• Significant transmittance of 65-80% in the range of 5.1-6.2
μm

16. Example
• IR Spectrum of a Thionated Polymer
Lens of film thickness 2  0.1 mm
• Dual-band SWIR/MWIR applications
• The numbers on this graph were not
adjusted to include anti-reflection
coating
*absorption likely due to hygroscopic substrates
used to encase our samples

17. About Us
o John Lester Miller, Board Member and Lead Consultant
• John has 40 years of experience in the photonics industry, authored 5 books, over 100
papers, serves as a chair at the largest infrared technology conference, and is a SPIE
fellow.
o Dr. Rinat Akhmetshin, Chief Science Officer and Inventor of the Brimstone
Lens™
• Rinat has a PhD in chemistry and decades of diverse executive experience to include the
commercial sale of Germanium.
oEdward Liebermann, Board Member and General Counsel
• Edward is an experienced international lawyer and former partner in the Coudert
Brothers and Pepper Hamilton law firms.
o Brett Rosenberg, Board Member and Chief Executive Officer
• Brett is a technology consultant with 20 years of experience in both the federal
government & commercial space. He is a decorated Marine Corps and Air Force veteran.