| Summary: | We present a low-noise (<10 µ<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>rad</mi><mo>/</mo><msqrt><mi>Hz</mi></msqrt></mrow></semantics></math></inline-formula>) broadband Faraday Rotation Spectroscopy method which is feasible for near-ultraviolet through near-infrared wavelengths. We demonstrate this in the context of a high-precision spectroscopy experiment using a heated Pb vapor cell and two different lasers, one in the UV (368 nm) and a second in the IR (1279 nm). A key element of the experimental technique is the use of a uniaxial single crystal CeF<sub>3</sub> Faraday modulator with excellent transmission and optical rotation properties across the aforementioned wavelength range. Polarimeter performance is assessed as a function of crystal orientation and alignment, AC modulation amplitude, laser power, and laser wavelength. Crystal-induced distortion of the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mrow><mo>(</mo><mn>6</mn><msup><mi>p</mi><mn>2</mn></msup><mo>)</mo></mrow><mn>3</mn></msup><msub><mi>P</mi><mn>0</mn></msub><mo>→</mo><msup><mrow><mo>(</mo><mn>6</mn><msup><mi>p</mi><mn>2</mn></msup><mo>)</mo></mrow><mn>3</mn></msup><msub><mi>P</mi><mn>1</mn></msub></mrow></semantics></math></inline-formula> (1279 nm) and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mrow><mo>(</mo><mn>6</mn><msup><mi>p</mi><mn>2</mn></msup><mo>)</mo></mrow><mn>3</mn></msup><msub><mi>P</mi><mn>1</mn></msub><mo>→</mo><msup><mrow><mo>(</mo><mn>6</mn><mi>p</mi><mn>7</mn><mi>s</mi><mo>)</mo></mrow><mn>3</mn></msup><msub><mi>P</mi><mn>0</mn></msub></mrow></semantics></math></inline-formula> (368 nm) spectral lines due to misalignment-induced birefringence is discussed and modeled using the Jones calculus.
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