Improvement Case Study
Detecting Side Mode Behavior in Single-Mode Lasers
Customer’s Issue
The customer wanted to measure weak, randomly occurring side modes that appeared along the same axis as the main peak of a single-mode laser, using an optical spectrum analyzer. Adjusting the instrument’s intensity range to detect side modes can cause the main peak to saturate, burying the side modes in the signal, or distorting their shape, and preventing accurate measurement.
Advantages of Shimadzu Products
★Advantage 1: Weak Side Modes can be Measured Even when the Main Peak is Saturated
The SPG-V500 employs CMOS sensors that suppress signal interference (crosstalk) between adjacent pixels even when the main peak saturates. Even if the main peak is saturated, the SPG-V500 can detect side modes clearly.
As a result, the instrument can be used to evaluate lasers used for applications such as Raman spectroscopy, where side modes would affect instrument performance.
★ Advantage 2: Simultaneous Measurement of Multiple Wavelengths, Enables Spectral Behavior to be Captured with High Resolution
Based on the polychromator principle, the SPG-V500 is equipped with an array sensor that continuously acquires data across a specific wavelength range, enabling observation of spectral behavior.
With a wavelength resolution of approximately 0.02 nm (Typ.), it can measure the main peak and side modes, even if their wavelengths are extremely close or the signals are very weak.
Benefits of Using Shimadzu Products and Customer Feedback
We successfully detected side modes that we had previously been unable to measure. Side modes, previously obscured by high-intensity light and difficult to separate, were surprisingly easy to detect with the SPG-V500. Simply shining the light into the instrument revealed a clear peak almost immediately. Thanks to its ability to detect spectral behavior, we can now measure side modes regardless of when they occur. The real-time measurement and detection capabilities of the SPG-V500 have freed us from the struggles we faced when making measurements.
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