The molecular strong-field approximation is employed to study high-order harmonic generation by linear and planar polyatomic molecules exposed to an orthogonally polarized two-color laser field, which consists of two orthogonal linearly polarized components with commensurable frequencies. For such a driving field, we find that the harmonic emission rate and the shape of the spectrum strongly depend on the laser-field parameters including the relative phase and the ratio of the intensities of the two components. The values of the relative phase that correspond to the optimal harmonic emission rate, as well as the cutoff position, can be assessed using a classical model. The possible production of an isolated attosecond pulse is investigated. For suitable symmetry of the laser field an attosecond pulse train with only one attosecond pulse per cycle can be generated. Depending on the frequencies of the two field components, the molecular symmetry properties and the orientation of the molecule with respect to the field, the even harmonics can be absent from the spectrum, which can be used to determine the molecular orientation. The emitted harmonics are elliptically polarized and their ellipticity depends on the molecular orientation.

分子强场近似用于研究线性和平面多原子分子暴露于正交偏振双色激光场产生的高次谐波，该激光场由两个具有可公度频率的正交线性偏振分量组成。对于这样的驱动场，我们发现谐波发射率和光谱形状在很大程度上取决于激光场参数，包括相对相位和两个分量的强度比。对应于最佳谐波发射率的相对相位值以及截止位置，可以使用经典模型进行评估。研究了孤立阿秒脉冲的可能产生。对于激光场的适当对称性，可以生成每个周期只有一个阿秒脉冲的阿秒脉冲序列。根据两个场分量的频率、分子对称性和分子相对于场的取向，光谱中可能不存在偶次谐波，这可用于确定分子取向。发射的谐波是椭圆偏振的，它们的椭圆度取决于分子取向。