10 Nov 2006
Founded on a strong tradition of solid-state physics and crystal growth, Warsaw has long been a key player in the optoelectronics sector. James Tyrrell and the DTI's central Europe expert, George Tomka, report from Poland's capital.
Being known as a region of expertise is nothing new to Warsaw. The capital's solid-state physicists were instrumental in the success of the Soviet space programme, and long before that the city was home to crystal-growth pioneer Jan Czochralski. Today, a new generation of Poles are looking to combine their scientific strengths with the opportunities of EU membership.
Laser diode specialist TopGaN is recognized as one of the most innovative high-tech companies in Poland. Formed in 2001, the Warsaw-based firm was the first in the world to offer a blue laser (415 nm) based on a near-defect-free gallium nitride (GaN) crystal. The devices have the advantage of high optical power (200 mW continuous-wave and 2 W pulsed) and benefit from simpler production than their counterparts grown on sapphire substrates. Applications include data storage, projection TV and spectroscopy.
The technology for growing single GaN crystals was developed by Sylwester Porowski and his team at Warsaw's High-Pressure Research Centre (UNIPRESS), one of TopGaN's major shareholders. According to Porowski, the crystal's principal feature is a very low dislocation density of about 100/cm2. He adds that this is several orders of magnitude less than GaN layers that are grown by rival producers on foreign substrates such as sapphire or silicon carbide.
To make the crystals, the group had to develop high-pressure furnaces operating at up to 50 kbar and between 1500 and 1800 °C. "High pressure allows us to introduce sufficient nitrogen to dilute the gallium," explained Piotr Perlin, head of TopGaN's laser department. "The challenge is keeping the temperature and pressure stable for 100–200 h."
Perlin reveals that the ability to design a chamber with a multizone temperature profile is critical. UNIPRESS sells scaled-down versions of its high-pressure reactor for around $100,000 (€79,630).
Formed a few years before TopGaN, Solaris Laser is another of Warsaw's high-tech firms that is finding success. The company was created in 1991 by scientists from Warsaw University of Technology (WUT) and now employs 35 people. It is known for building up laser marking and laser-coding systems.
A turning point for the firm came at the end of 1998 when it switched its focus from the industrial laser market to the packaging sector. "We realized that we could develop a system for laser marking on-the-fly," said Pawel Kowalczyk, Solaris' sales and marketing manager. "Thanks to high-performance scanning technology and drive electronics, we were able to write in the x and y directions and follow the product."
The change in strategy proved its worth in 2001 when the firm's vector-marking system became a big hit with the brewing industry's bottling lines. Until then, beer bottles had been coded using a masking set-up that could only offer identical marks.
"With a vector-based system you have the freedom to write best-before dates, hours and minutes, batch numbers, or whatever you want," explained Kowalczyk. Solaris' 30 W CO2 laser system can mark 10,000 –20,000 bottles/h with two lines of text or numbers, and its high-performance 100 W set-up is capable of handling 70,000 bottles/h. By focusing on high-speed systems for demanding applications, the firm has so far managed to stay ahead of low-cost Asian competition.
Situated near Solaris is Laser Instruments (CTL) – a producer and developer of medical lasers. The 25 employee-strong firm has been in business for 15 years and, like Solaris, it was founded by WUT staff. CTL began by building semiconductor laser-based systems for physiotherapy, followed by CO2 laser instruments aimed at surgical applications. The company says that in 1993 it was the first in the world to offer an erbium:YAG laser for hard tissue drilling in the dental sector.
CTL is successful and has sold over 5000 medical lasers in Poland, but the medical market presents a dual challenge. "It's not enough to just have a good understanding of lasers," said Marcin Pokora, CTL's marketing director. "You must also appreciate the specific restrictions and regulations."
Somewhat alarmingly for Poland's medical instrument manufacturers, the nation's medical certification changed overnight when the country joined the EU on 1 May 2004. Fortunately for CTL, its business was shielded to a certain extent thanks to the firm's local certification in countries such as Korea, Germany and Romania. Today, DNV, a notified body in Norway approves CTL's products and employs Polish speakers to help simplify the process.
Polish workers are well-sought-after by foreign firms and organizations, and it is no different in the photonics sector. "Poland's universities provide a good base to select employees, but talent is increasingly being lost overseas," confirmed Pokora. "[To fill the gap] our policy is to look to our neighbouring countries, such as the Ukraine, and offer temporary appointments that suit overseas workers." Pokora also lists Lithuania and Belarus as having employees with highly valued laser expertise.
To generate more homegrown opportunities, the Polish government is taking steps to mix research and business thinking. "Recently, the education structure has started to change, with options to combine science and industry," commented Pokora. "But there is still no good model to do this – we need to push the idea of innovation and creating spin-offs."
One firm that has overcome substantial hurdles is VIGO System, a developer of low-noise, high-speed mid- (2–8 μm) and long- (8–16 μm) wavelength infrared detectors. Jozef Piotrowsk is the architect of the firm's revolutionary uncooled technology, which made its debut at CLEO back in 1980 and placed VIGO on a world stage. Thanks to their unmatched performance, VIGO's detectors were snapped up at the show by US distributor Boston Electronics – the successful relationship continues today.
This revenue stream was a breath of fresh air for the team which, at that stage, was working within the constraints of a government organization. Poland's economic collapse after the fall of communism provided the opportunity to buy production equipment at bargain prices. The timing was key, as to start the company today would require millions of dollars of financing.
"Even two or three years ago it was very hard to find investment," commented Miroslaw Grudzien, one of VIGO's three founders. "The Polish banking system is reluctant to finance high-tech companies, because they are unwilling to accept the risk." Fortunately for the firm, VIGO's uncooled detector won "Polish product of the future" in the late 1990s, giving the company access to credit at a favourable interest rate and the opportunity to expand its operation.
In 2002, VIGO purchased an MOCVD reactor from German firm AIXTRON. The new equipment allowed the team to create complex HgCdTe heterostructures with up to 17 layers optimized for a given wavelength. In just eight hours, VIGO's engineers can prepare enough material for around 2000 detectors.
The resulting products are ideal for warning-tank crews when they are being illuminated by a weapon's rangefinder. Coupled to system electronics, units can trigger antimeasures such as smoke sprays for scattering incoming laser beams. EU membership has opened up the firm's market to include European military suppliers and it is now building a relationship with NASA to develop detectors for satellite use.
The Polish capital is home to no fewer than three universities: the Military University of Technology (WAT), Warsaw University and the WUT.
WAT's Institute of Optoelectronics (IOE), which is grouped into lasers, thermodetection and optoelectronics, comprises 90 scientists and 70 engineers and technicians. IOE is a centre for R&D and education and its interests range from the remote detection of biological and chemical agents through to the cleaning of fine art. According to the IOE's director, Henryk Fiedorowicz, the first laser to be used in a medical application (in 1966) was developed at WAT. Other success stories include ultraviolet exposure meters that have been sold in Australia to protect against skin cancer.
Interferometry is a speciality of WUT and is being put to use by former SPIE president Malgorzata Kujawinska and her team at the Institute of Micromechanics and Photonics. Researchers are busy developing a miniature interferometer head for analysing laser-welded materials and determining the distribution of material constants at an interface – a key requirement for the aerospace industry. Ultimately, by working with Finnish packaging expert VTT, the group wants to come up with polymer-based, disposable modules that could cost as little as $0.10 (€0.08) each.
Kujawinska is switched on to the commercial opportunities of her research. "I don't like doing science purely for science's sake," she revealed. "It should also be about technology transfer." To help scientists take their work to the next level, the government has decided to fund a new class of "technology transfer" project. The research doesn't have to have industry funding, but must result in a prototype.
Warsaw's scientific community is keen to commercialize its expertise and is willing to tread the difficult path from lab to market. Along with the previously mentioned TopGaN, Solaris, CTL and VIGO, WUT spin-out Smarttech is another good example. Founded in 2000, the 3D shape-measurement specialist now numbers 10 staff and has attracted the interest of household names such as Bosch.
Using a white-light source coupled to a PC, Smarttech's ScanBright system projects a series of bright and dark stripes onto a specimen. "The object's curvature distorts the striped pattern, which can be used to reconstruct its geometry," explained Marcin Baczyk, one of the firm's engineers. "It's a technique adapted from temporal-phase-shifting interferometry."
Applications include the digital manipulation of archaeological artefacts and the creation of virtual museums stored on a PC. The system also suits reverse engineering, where documentation has to be created for parts of unknown geometry, and lends itself to machine vision. Baczyk adds that the laser-free technique is safe to use and a cost-effective alternative to co-ordinate measuring machines.
Taking the initiative
Various photonics networks and optical projects link Warsaw's universities and research institutes, including European initiatives such as the Network of Excellence on Micro-Optics (NEMO). Members include WUT's optics division, which is part of the faculty of physics and is headed by Tomasz Wolinski.
Wolinski's group has been combining liquid crystal and photonic-crystal fibre. "Liquid crystal allows you to boost the properties of photonic-crystal fibre," he told OLE. "You can vary the properties dynamically." Attributes such as wavelength, intensity and polarization can be manipulated by an external electrical field or through changes in temperature. Wolinski explains that these so-called photonic liquid-crystal fibres can be used as temperature and electrical field sensors, as tunable polarizers and as elements of polarization mode-dispersion compensators in optical telecommunications systems.
From universities to research institutes, it is impossible not to be overwhelmed by the vast amount of expertise up for grabs. Located in the south of the city, the Institute of Electron Technology (ITE) specializes in semiconductor technology. Financed through a combination of Polish, European and industry funding, the facility is a pool of processing talent that can be tapped by private firms and universities alike.
ITE employs almost 300 people across 11 divisions including photodetectors, silicon microsystems and nanostructure technology. Using on-site molecular-beam-epitaxy apparatus, staff are developing a range of semiconductor structures for devices such as VCSELs, resonant cavity LEDs and quantum dots. Other interests include the design of MOEMS silicon coolers for semiconductor lasers and the mapping of facet temperatures to monitor antireflective coating damage.
The Institute of Electronic Materials Technology (ITME) is another Warsaw-based organization with considerable technical know-how at its disposal. Formed in 1976, ITME now has 260 staff. The institute is a driving force in semiconductor crystal production as well as optical, piezoelectric and superconductive materials. It also manufactures active glasses, optical fibres, ceramic and composite materials.
ITME's expertise is held in extremely high regard. Speciality materials giant Umicore was so impressed that it established the joint venture ComSeCore in partnership with ITME to supply epi-ready compound semiconductor wafers and epitaxial InP-based products.
ITME also coordinates "Consortium Polish Optoelectronics", a network linking research institutes, technical universities and companies that aims to share facilities and knowledge between its members.
• This article originally appeared in the November 2006 issue of Optics & Laser Europe magazine.