Technology & market validation study for an infrared spectrometer based on multiphoton absorption

在所有激光实验室中，超快激光的光谱特性是最基本的测量，因为光谱及其光谱相位定义了脉冲的时间分布。虽然可以通过使用参考脉冲的干涉测量或涉及非线性光学过程的各种方法来恢复光谱相位，但光谱是用光谱仪测量的。在从紫外线到近红外的光谱范围内，硅基光谱仪具有高达4096像素的商用设备，可以高效地表征激光光源的光谱，从而实现高灵敏度和高光谱分辨率的测量。在1100 nm以上，商用光谱仪需要使用由不同材料制成的探测器，例如光谱范围高达2500 nm的InGaAs阵列。在InGaAs阵列的情况下，商业设备的像素数量被限制在512个，与基于硅的光谱仪相比，提供了较低的光谱分辨率。此外，这种材料对热噪声更敏感，因此需要一个冷却单元，如热电单元，以确保高灵敏度。这意味着与硅相比，商用InGaAs光谱仪的成本要高得多(根据选项，12K-25K美元与2K-5K美元)。**对于脉冲激光，多光子吸收发生在硅等材料中。在这里，我们建议使用这些工艺来开发一种名为“基于多光子吸收的红外光谱仪”的技术，利用硅中的双光子吸收来实现高达2200 nm的光谱测量，以及使用三光子来实现高达3300 nm的光谱测量。我们已经在1300到2000 nm之间验证了这项技术，其中来自硅探测器的信号仅与激光强度的平方成比例，表示双光子吸收。这项技术的优点是，它能够使用用于可见光/近红外光谱范围的传统探测器来表征红外脉冲激光的光谱特性，从而提供高灵敏度和高光谱分辨率，价格在6k$到8k$之间。技术和市场验证研究将有助于确认加拿大和外国公司对拟议技术转让和商业化的兴趣。

In all laser laboratories, spectral characterization of ultrafast laser is the most elementary measurement since the spectra and its spectral phase defines the temporal profile of the pulses. While the spectral phase can be retrieved through interferometry with reference pulses or various approaches involving nonlinear optical processes, the spectra is measured with a spectrometer. In the spectral range from ultra-violet to the near infrared, silicon based spectrometer are highly efficient to characterize the spectra of laser sources with commercial devices having up to 4096 pixels, enabling measurements with high sensitivity and spectral resolution. Above 1100 nm, commercial spectrometers require the use of detectors made of different materials, such as InGaAs arrays for the spectral range up to 2500 nm. In the case of InGaAs arrays, the number of pixels for commercial devices is limited to 512, providing a lower spectral resolution compared to silicon based spectrometer. In addition, this material is more sensitive to thermal noise thus requiring a cooling unit such as a thermoelectric one to ensure high sensitivity. This translates into much higher costs for commercial InGaAs spectrometers compared to silicon (12k-25k$ vs 2k-5k$ based on options).** For pulsed laser, multiphoton absorption occurs in material such as silicon. Here, we propose to use these processes to develop a technology entitled "Infrared spectrometer based on multiphoton absorption", to enable spectral measurements up to 2200 nm using two-photon absorption in silicon, and 3300 nm with three-photons. We have already validated this technology between 1300 and 2000 nm where the signal from a silicon detector simply scales with the square of the laser intensity, denoting a two-photon absorption. The advantage of this technology is that it enables the spectral characterization of infrared pulsed laser using conventional detectors used for the visible/near-infrared spectral range, thus offering high sensitivity and high spectral resolution, with a price in the range of 6k$ to 8k$. The technology & market validation study will help to confirm the interest of Canadian and foreign companies for the tech transfer and the commercialization of the proposed technology.******