Exhibit 99.1

FOR IMMEDIATE RELEASE

Contacts:
SDL, INC. FINANCIAL RELATIONS BOARD
Donald R. Scifres, Chairman and CEO Lisa Horn Chainey/Marcia Nakamura (general
info)
Michael L. Foster, VP Finance and CFO Susan Katz (investor contact)
(408) 943-9411 Chris Wood (media)
(415) 986-1591

SDL, INC. ANNOUNCES THE AGREEMENT TO ACQUIRE
PHOTONIC INTEGRATION RESEARCH, INC. (PIRI),
LEADER IN PLANAR WAVEGUIDE TECHNOLOGY SDL Expands
Product Portfolio with Entree to the High Growth Passives Market

SAN JOSE, CALIFORNIA - MAY 10, 2000 - SDL, Inc. (Nasdaq: SDLI) announced today
the signing of a definitive acquisition agreement with the shareholders of
Photonic Integration Research, Inc. (PIRI) valued at $1.8 billion. PIRI, a
privately held company located in Columbus, Ohio, is a leading manufacturer of
arrayed waveguide gratings (AWGs) that enable the routing of individual
wavelength channels in fiber optic systems. These products are used in optical
multiplexing (mux) and demultiplexing (demux) applications for dense wavelength
division multiplexed (DWDM) fiber optic systems. The acquisition expands SDL's
traditional role as a leader in active components in fiber optic systems to that
of a leader in advanced passive components. Further, the acquisition of PIRI
responds to the needs of SDL's customers going forward, by adding a critical
silicon wafer based optical integration technology which is expected to improve
performance and lower costs in next generation DWDM systems.

The acquisition agreement provides for a $31.25 million cash payment and the
issuance of approximately 10.2 million shares of SDL, Inc. stock, based on the
May 9, 2000 SDL closing stock price, in exchange for all of the stock of PIRI;
the exact number of shares will not be determined until closing. Completion of
the transaction is subject to customary closing conditions, including government
and regulatory approval, and is expected to close by the end of the second
quarter. The transaction, excluding acquisition-related charges and amortization
of intangible assets, is expected to be accretive from the date of closing.

PIRI will continue to operate as a wholly owned subsidiary of SDL, Inc. In the
quarter ended March 31, 2000, PIRI achieved revenues in excess of $20 million
and currently has 133 employees. Dr. Tadashi Miyashita, President of PIRI, is
expected to continue with SDL as the General Manager of the SDL subsidiary and
will report to Greg Dougherty, chief operating officer of SDL.

Donald R. Scifres, CEO and chairman of SDL, Inc. stated, "We believe PIRI is the
established leader in the rapidly growing market for AWG devices. As the channel
count in DWDM fiber optic systems continues to increase towards several hundred
DWDM channels and as the channel spacing continues to decrease towards 100 and
50 GHz, AWG products are expected to become the preferred technology over
dielectric filter based wavelength mux and demux products for advanced systems.
As a result of the trend towards higher channel count systems, RHK, an industry
consulting firm, has estimated that AWG products will be a $1.2 billion market
in 2003, with a CAGR of approximately 60 percent. We are pleased to be able to
acquire PIRI at the beginning of a cycle with high projected market growth."

Scifres continued, "SDL is also a strong believer in optical integration
technologies. The power of integrated circuit style manufacturing processes
utilized in the silica waveguide technology available at PIRI is crucial for
next generation product development. Going forward, we expect to integrate more
advanced devices such as variable optical attenuators, optical switches and
optical add/drop multiplexers with the AWG products. This optical integration is
expected to improve product performance while lowering manufacturing costs,
thereby providing the best value for our customers."

Dr. Miyashita added, "By combining with SDL, we are teaming with a market leader
which we believe will help us to expand our manufacturing and customer base. SDL
has also maintained a core group of scientists in the field of silica waveguide
technology which will further complement our technical expertise. We believe
that with SDL as our partner, we are well positioned in a high growth market.
This is a win for our current customers, and our employees as well."

About PIRI

PIRI, formed in 1987 by NTT Corporation, Mitsubishi Corporation and Battelle,
who together with Mitsubishi International Corporation are the current
shareholders, is the leading supplier of AWG products and silica waveguide
technology used in fiber optic mux/demux products. PIRI also offers a line of
other products including thermo-optic switches used in optical add/drop
multiplexers, thermo-optic based variable optical attenuators (VOAs) used in
gain equalization, and optical splitters used for distribution of the optical
signals. PIRI's products are applicable to the undersea, long haul and metro
markets.

About SDL
SDL's products power the transmission of data, voice and Internet information
over fiber optic networks to meet the needs of telecommunications, DWDM, cable
television and satellite communications applications. They enable customers to
meet the bandwidth needs of increasing Internet, data, video and voice traffic
by expanding their fiber optic communications networks more quickly and
efficiently than would be possible using conventional electronic and optical
technologies. SDL's optical products also serve a variety of non-communications
applications, including materials processing and printing. Additional
information about SDL, Inc. is available on the Internet at www.sdli.com.

Statements in this press release which are not historical including statements
regarding SDL's or management's intentions, hopes, beliefs, expectations,
representations, projections, plans or predictions of the future are
forward-looking statements within the meaning of the Private Securities
Litigation Reform Act of 1995. Such statements include statements regarding the
acquisition expanding SDL's role to that of a leader in advanced passive
components, and the ability of the merged companies' silicon wafer-based optical
integration technology to respond to customers' needs and improve performance
and lower costs in next generation DWDM systems. It is important to note that
the Company's actual results could differ materially from those in any such
forward-looking statements. Factors that could cause actual results to differ
materially include competitors' advances in passive components, risks related to
uncertainties in or failure of the company's products to achieve improved
performance, lower costs or meet customer product specifications and market
requirements, and the risk factors listed from time to time in the Company's SEC
reports including but not limited to, the annual report on Form 10-K for the
year ended December 31, 1999, and the quarterly report on Form 10-Q for the
quarter ended March 31, 2000.