The traditional view holds that cluster cooperation could be driven by top-down initiatives, public incentives and management who network, liaison between similar formal and informal structures and associations in other countries to reach out to individual SMEs and create match-making leads.

However, other, more bottom-up ways of cooperation are becoming possible due to the direct links established by individual cluster members with their counterparts along the relevant value chains. These business-to-business contacts matching the complementarity of other companies involved along the supply chains become the initiators of cross-cluster cooperation. In some, though still rare instances, such companies are becoming members of the regional clusters in other parts of Europe where they have established links with business partners as value-added resellers or integrators.

One such company is TOPAG Lasertechnik GmbH from Darmstadt (Germany), a supplier for lasers, laser-optics and optical measuring equipment. In 2006 the company started cooperating with EKSMA Optics from Vilnius (Lithuania), a manufacturer and global supplier of precision optical components and optical systems (though the start of the cooperation with a Vilnius laser community goes back to the early 1990s). Ever since two companies have been involved bringing to market a variety of laser components, e.g. special optics for high power lasers, opto-mechanical components for optics positioning, laser and nonlinear frequency conversion crystals, electro-optical Pockels cells. Other applications include laser beam shaping and beam profile homogenising using special free form lenses developed by TOPAG company. Some of the production processes for beam shaping lenses such as anti-reflection coatings are applied by EKSMA Optics.

As a result of a close long-term collaboration between two companies (taking place over more than a decade) in 2014 TOPAG Lasertechnik GmbH was invited by its Lithuanian counterpart to join the Laser and Engineering Technologies Cluster (LITEK) in Vilnius (Lithuania). This cluster was setup in 2010 to include some of the major laser industry companies in Vilnius and in 2014 has established the cluster R&D facilities to host the shared industrial laboratories and support the technology development of the cluster companies. Through the involvement with EKSMA Optics TOPAG also became a part of this cluster network and benefited from some marketing, shared channels and cross-sales activities.

Prior to that TOPAG co-founded the optics competence network Optence (founded in 2001) in its own region (Hesse and Rhineland Palatinate) which developed into a regional photonics cluster with members from outside the region as well (including the cooperation with companies in Switzerland, the Netherlands and the UK). Thus, when in 2016 the need arises for Optence to expand its cluster networking reach beyond Germany LITEK came first on the list due to the ongoing links between TOPAG and EKSMA Optics. A letter of intent was signed and further collaboration efforts are foreseen bringing together two photonics clusters which initially had nothing in common, except the dedicated contact between Dr. Udo Umhofer, CEO or TOPAG and Daugirdas Kuzma, Marketing Director, of EKSMA Optics. This case clearly shows that the cross-cluster cooperation is often driven by SMEs themselves and that the cluster managers should pay a close attention to them in order to spot bilateral connections early on, so that further networking efforts could be built upon them. To that end the LASER-GO partnership is considering Optence as a future member of the consortium.