Описание хроматической дисперсии с помощью пертурбативного подхода через коэффициенты Тейлора подходит для задач оптимизации, где необходимо сбалансировать дисперсию от нескольких различных систем. Например, в лазерных усилителях, импульсы сначала растягиваются во времени, чтобы избежать оптического повреждения кристаллов. Затем, в процессе усиления энергии, импульсы накапливают неизбежную линейную и нелинейную фазу, проходя через различные материалы. Наконец, импульсы сжимаются в различных типах компрессоров. Для того чтобы сбросить любые остаточные высшие порядки в накопленной фазе, отдельные порядки дисперсии обычно измеряются и балансируются. Для однородных систем такое пертурбативное описание часто не требуется (например, для распространения импульса в волноводах или оптических волокнах). Дисперсионные порядки сводятся к аналитическим уравнениям, которые идентичны преобразованиям типа Лаха-Лагера[3][4].
Порядки дисперсии определяются разложением Тейлора фазы или волнового вектора.


Производные дисперсии для волнового вектора
и фазы
могут быть выражены как:
,

Производные любой дифференцируемой функции
в пространстве длин волн или частот определяются через преобразование Лаха как:

Матричные элементы преобразования являются коэффициентами Лаха: 
Записанное для дисперсии групповой скорости GDD, приведенное выше выражение утверждает, что постоянная длины волны GGD будет иметь нулевые высшие порядки. Высшие порядки, полученные из GDD, являются:

Подстановка уравнения (2), выраженного для показателя преломления
или оптического пути
, в уравнение (1) приводит к аналитическим выражениям для порядков дисперсии. В общем случае дисперсия
порядка POD является преобразованием типа Лагерра отрицательного второго порядка:

Матричные элементы преобразований представляют собой беззнаковые коэффициенты Лагерра порядка минус 2 и имеют вид: 
Первые десять порядков дисперсии, записанные в явном виде для волнового вектора:

Групповой показатель преломления
определяется как:
.









В явном виде, записанные для фазы
, первые десять порядков дисперсии могут быть выражены как функция длины волны с помощью преобразований Лаха (уравнение (2)) в виде:









