Intra-cavity spectral shaping based on optical rotatory dispersion in a broadband Ti : S regenerative amplifier

Abstract

We theoretically present a passive method for intra-cavity spectral shaping in a broadband Ti : S regenerative amplifier on optical rotatory dispersion (ORD). Besides a polarization-dependent Ti : S gain crystal, implementing the method requires a broadband half-wave plate and a wedge pair made of an optical rotator crystal for an adjustable ORD. Our calculations show inducing proper ORD allows the amplifier to boost an 800 nm pulse from sub-nJ up to 3.18 mJ with a bandwidth of 94.5 nm without peak wavelength shift or spectral narrowing. For a certain ORD, this method allows us to get tunable broadband amplification with almost constant output pulse energy by simply rotating the half-wave plate. In spite of its flexibility in controlling the output spectrum of the amplifier, this method is very simple to align.

Spectral polarization-encoding of broadband laser pulses by optical rotatory dispersion and its applications in spectral manipulation*

“…In order to avoid the spectral narrowing, efforts are usually made to suppress the laser gain for the spectral components around the central wavelength of the seeded pulses, meanwhile, to increase the gain for those far away from the central wavelength. Correspondingly, by use of a BHW and a block of quartz crystal, we applied our SPE to a Ti:S regenerative amplifier [21] where the seed pulses are amplified with σ -polarization for the spectral components around the central wavelength, and with π-polarization for those far away from the central wavelength.…”

“…( 1) and ( 2) and Table 1 of Ref. [21] when using an 11-mmthick quartz plate and setting the σ -polarization wavelength λ σ = 0.82 µm. As shown by the blue solid-triangle marks, the amplified pulse bandwidth is initially 44.1 THz, and increases to 49.1 THz with the pass number N up to 30.…”

Carrier-envelope phase stability of a polarization-encoded chirped pulse Ti:Sapphire amplifier

“…In a PE-CPA, contrary to a conventional CPA, both πand σ-axes of the Ti:Sa crystals are used, leading to the reshaping of the gain spectrum. The polarization state of the seed spectrum is encoded before amplification using the optical rotatory dispersion (ORD) effect in a quartz crystal [13,14]. The central part of the seed spectrum is oriented close to the σ-axis, while the spectral wings are rotated towards the π-axis (Fig.…”

Broadband spectral shaping in regenerative amplifier based on modified polarization-encoded chirped pulse amplification

“…Recently, Xu et al theoretically showed that a novel method based on optical rotatory dispersion (ORD) and polarization-dependent gain characteristic of Ti:Sa could be used to suppress the spectral gain narrowing in RAs 22) and multi-pass amplifiers. 23) Kalashnikov et al experimentally applied this method, referred to as polarization-encoded chirped pulse amplification (PE-CPA), in a six-pass Ti:Sa amplifier, which yielded a gain of ∼200 and 7 mJ amplified pulse with an 82 nm (FWHM) bandwidth.…”