Tim Mammen
Chief Financial Officer and Senior Vice President at IPG Photonics
Thank you, Eugene, and good morning, everyone. My comments generally will follow the earnings call presentation, which is available on our Investor Relations website. I will start with the financial review on slide 4. Revenue in the fourth quarter was $334 million, down 8% year-over-year due to foreign currency headwinds, which accounted for approximately 7% of the decline. Our divestiture of noncore telecom product lines negatively impacted revenue growth by approximately 2%. We also saw lower sales in general industrial applications in China and Europe, which were nearly offset by strength in emerging growth products.
Revenue from materials processing applications decreased 6% year-over-year, and revenue from other applications decreased 23%, with strength in medical offset by weaker advanced application sales and the telecom divestiture. During the quarter, we conducted a review of our Russian operations and recognized significant charges related to inventory, long-lived asset impairments and restructuring. These charges are a result of the lower level of activity we expect given the increasing limitation of sanctions. GAAP gross margin was 18.2%, a decrease of 2,730 basis points year-over-year due to $74 million inventory write-downs and other charges related to our Russian operations.
Excluding these inventory-related charges, gross margin was approximately 40%. We provide adjusted results in the appendix on slide 11 of the presentation. Please note that adjusted results are non-GAAP items and while we believe they may be meaningful, these results should not be considered a substitute for GAAP measures. Gross margin was also negatively impacted by higher inventory provisions in the rest of the world, the strong dollar, scrap, shipping costs and import duties. These were partially offset by increased absorption of manufacturing costs in the quarter as we continue to build our inventories of safety stock.
We are working to offset the impact of changes in the supply chain and manufacturing footprint on our gross margins by investing in automation and investing in locations with lower costs in Germany and the U.S., such as Poland or Italy. We remain committed to our long-term gross margin target of 45% to 50%. Additionally, both revenue and gross margin were impacted by currency translation headwinds. If exchange rates relative to the U.S. dollar had been the same as one year ago, we would have expected revenue to be $25 million higher and gross profit to be $16 million higher.
Foreign currency transaction gains related to remeasuring foreign currency assets and liabilities to period-end exchange rates benefited operating expenses by $7 million or $0.12 per diluted share. GAAP operating loss was $88 million, and operating margin was a negative 26.5%. The net loss in the quarter was $93 million or $1.91 per diluted share. As mentioned above, we had a number of unusual items impacting our operating income and earnings per share in the quarter. There is a $74 million or $1.21 per diluted share impact from inventory-related charges, $79 million or $1.30 share impact from impairment of long-lived assets in Russia and other restructuring charges of $10 million or $0.16 per diluted share.
There was also a gain on sale of our corporate aircraft of $10 million or $0.16 per diluted share. Excluding these special items and the discrete tax impact of these items, adjusted diluted EPS was $1.08. Moving to slide 5; sales of high-power CW lasers decreased 13% and represented approximately 39% of total revenue. Sales of ultra-high power lasers above 6 kilowatts represented 47% of total high-power CW laser sales. The decline was primarily due to lower demand in cutting applications in China and Europe, which was only partially offset by growth in welding applications across most major geographies.
Pulsed laser sales decreased 9% year-over-year as a result of lower demand in cutting and marking applications, partially offset by strong sales into solar cell manufacturing. System sales increased 19% year-over-year, driven by growth in laser systems and higher sales of LightWELD. Medium power laser sales decreased 37%, while QCW laser sales were down 20% -- 21% year-over-year, negatively impacted by lower sales to consumer electronics and general industrial applications. Other product sales were nearly flat as growth in medical was offset by the divestiture of the telecom business and lower revenue in advanced applications.
Looking at our performance by region on slide 6; revenue in North America decreased modestly by 3% with growth in cutting, welding and medical applications, offset by lower sales in non-laser systems, advanced applications as well as the telecom divestiture. In Europe, sales decreased 21% as a result of lower demand across all major materials processing applications due to weaker macroeconomic conditions. Currency translation also negatively impacted sales in the region.
Revenue in China decreased 15% year-over-year as growth in welding primarily for EV battery applications was more than offset by continued softness in the cutting market, increased local competition and currency headwinds. We estimate that COVID-related restrictions in China impacted fourth quarter revenue by approximately $7 million and bookings by approximately $14 million. Moving to a summary of our balance sheet on slide 7; we ended the quarter with cash, cash equivalents and short-term investments of $1.2 billion and total debt of $16 million.
Cash provided by operations was $42 million during the quarter and capital expenditures were $26 million in the quarter. During the quarter, we repurchased shares to a total of $117 million, while continuing to maintain a strong balance sheet, we have returned $500 million of capital to shareholders with our ongoing stock repurchases in 2022, which represents more than half of our total share repurchases since 2016.
Our inventories declined due to the inventory write-down in Russia with some improvements to the electronic supply chain, a decrease in required safety stock as we continue to increase production of components in Europe and North America and a focus on improving our inventory management, we plan to stabilize and then reduce the investment in inventory during 2023. Our capex was $26 million in the quarter and $110 million for the full year. We expect 2023 capex to be in the range of $140 million to $160 million.
The expected expenditures in 2023 are at a higher rate than we expect longer term as we are building and equipment for production capacity expansion to increase production outside of Russia. Capex also includes investments in R&D, sales and service in North America, Germany and Asia. Moving to outlook on slide 9; fourth quarter book-to-bill was slightly below 1. We saw continued softness in orders in Europe and China, primarily due to uncertain macroeconomic conditions, which impact demand in general industrial markets.
Media macroeconomic indicators for Europe, China and the U.S. remain subdued, but conditions appear to be more stable in Europe and the U.S., and there is an expectation of increasing activity in China later this year. Additionally, we are benefiting from growth opportunities created by major macro trends such as electric vehicle battery manufacturing and renewable energy. We're seeing continued strong orders in e-mobility and welding applications, which are not being impacted by the economic uncertainty.
Furthermore, LightWELD and medical products continue to ramp up, presenting future growth opportunities for IPG. For the first quarter of 2023, IPG expects revenue of $310 million to $340 million. The company expects the first quarter tax rate to be approximately 26%. IPG anticipates delivering earnings per diluted share in the range of $0.90 to $1.20 with approximately 48 million diluted common shares outstanding.
We continue to expect currency headwinds and estimate that the first quarter revenue guidance is reduced by about $9 million due to the strength of the U.S. dollar in the current quarter as compared to the first quarter of 2022. As discussed in the safe harbor passage of today's earnings press release, our guidance is based upon current market conditions and expectations, assumes exchange rates referenced in our earnings press release and is subject to risks outlined in the Safe Harbor and the company's reports with the SEC.
With that, we'll be happy to take your questions.