Exhibit 99.1
February 16, 2021
Board
of Directors
Coherent Inc.
5100 Patrick Henry Drive
Santa Clara, CA 95054
To the Members of the Board:
We appreciate the constructive and professional engagement of Coherents team with us over the past week as we discussed together the substantial merits
of a business combination with MKS Instruments.
We have long admired Coherent, its leadership and dedicated employees, and our meetings last week have
only reinforced our view that together we will create highly attractive value for the stakeholders of both of our companies. We believe that combining our strengths at this time will position the merged company to accelerate the technology roadmap
for the next phase of growth, especially as the challenges facing the sector become increasingly complex.
We are mindful that you are evaluating multiple
proposals at this time and want to reiterate our belief that MKS would be the ideal partner for Coherent, from both a strategic and cultural perspective; and we are confident a transaction with MKS can be completed in a timely fashion.
Compelling Strategic Rationale
MKS offers a true
strategic fit that would allow our teams to continue to advance our shared vision in contrast to the other potential merger partners, where strategic fit is unclear given their core telecom-focused businesses. The combination of our companies
would create a global photonics leader with a world-class technology portfolio, complementary products, ground-breaking innovation, proven operational capabilities, a highly talented team, and deep customer relationships.
As the world moves towards the broad adoption of laser-based manufacturing processes, the markets we serve are expanding rapidly and the pace of required
innovation to meet customers needs is accelerating. United by our shared vision and extensive knowledge of, and commitment to, the photonics industry, our proposed combination would enable us to more effectively meet these challenges with the
complementary R&D strengths to create products necessary to solve our customers most demanding problems, faster.
Significant Shareholder
Value Creation Opportunities, Rooted in a Shared Culture and Commitment to Our Industry
We are confident MKS and Coherent together would create the
most value for your shareholders as owners of the combined company. We benefit from a deep and experienced management team who have been integral to our demonstrated record of achieving superior profitability through business cycles. We are driving
significant organic growth, and even in down cycles, we have proven our ability to generate strong profitability and cash flow, as our capital equipment-light operational structure has enabled us to nimbly and effectively manage our cost structure.
In fact, in 2019 we experienced a cyclical trough in both our Semiconductor and Advanced Markets, yet we still delivered greater free cash flow than any peak year in our history prior to 2017.